timolol/brimonidine (Rx)

Elevated IOP in Patients with Glaucoma or Ocular Hypertension

1 gtt in affected eye(s) BID approximately 12 hours apart

Dosing considerations

If more than one topical ophthalmic product is to be used, the different products should be instilled at least 5 minutes apart

Elevated IOP in Patients with Glaucoma or Ocular Hypertension

<2 years: Contraindicated

≥2 years old: 1 gtt in affected eye(s) BID approximately 12 hours apart

Dosing considerations

If more than one topical ophthalmic product is to be used, the different products should be instilled at least 5 minutes apart

Contraindicated (8)

• isocarboxazid

  isocarboxazid, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• linezolid

  linezolid, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• phenelzine

  phenelzine, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• procarbazine

  procarbazine, brimonidine. Mechanism: unknown. Contraindicated.

• rasagiline

  rasagiline, brimonidine. Mechanism: unknown. Contraindicated. Brimonidine should not be used in patients receiving MAO inhibitors.

• selegiline

  selegiline, brimonidine. Mechanism: unknown. Contraindicated. Coadministration is contraindicated.

• selegiline transdermal

  selegiline transdermal, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• tranylcypromine

  tranylcypromine, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

Serious - Use Alternative (35)

• acebutolol

  acebutolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  artemether/lumefantrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• atenolol

  atenolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• betaxolol

  betaxolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• bisoprolol

  bisoprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• carvedilol

  carvedilol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• celiprolol

  celiprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• clonidine

  clonidine, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• dacomitinib

  dacomitinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• digoxin

  digoxin, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• diltiazem

  diltiazem, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• epinephrine

  timolol increases effects of epinephrine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• epinephrine racemic

  timolol increases effects of epinephrine racemic by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• esmolol

  esmolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• fexinidazole

  fexinidazole, timolol. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to induce bradycardia. .

• fluoxetine

  fluoxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• givosiran

  givosiran will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• iobenguane I 131

  timolol will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.

• labetalol

  labetalol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• lofexidine

  lofexidine, timolol. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.

• lumefantrine

  lumefantrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• mavacamten

  timolol, mavacamten. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Expect additive negative inotropic effects of mavacamten and other drugs that reduce cardiac contractility.

• metoprolol

  metoprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• nadolol

  nadolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• nebivolol

  nebivolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• paroxetine

  paroxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• penbutolol

  penbutolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• pindolol

  pindolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• propranolol

  propranolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• quinidine

  quinidine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• rivastigmine

  timolol increases toxicity of rivastigmine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive bradycardia effect may result in syncope.

• sotalol

  sotalol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.

• umeclidinium bromide/vilanterol inhaled

  timolol, umeclidinium bromide/vilanterol inhaled. pharmacodynamic antagonism. Avoid or Use Alternate Drug. If a beta-blocker must be used in patients with COPD taking a beta-agonist, consider using a beta-blocker that is beta-1 selective .

• verapamil

  verapamil, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• vilanterol/fluticasone furoate inhaled

  timolol, vilanterol/fluticasone furoate inhaled. pharmacodynamic antagonism. Avoid or Use Alternate Drug. If a beta-blocker must be used in patients with COPD taking a beta-agonist, consider using a beta-blocker that is beta-1 selective .

Monitor Closely (220)

• acebutolol

  acebutolol and timolol both increase serum potassium. Use Caution/Monitor.

• aceclofenac

  timolol and aceclofenac both increase serum potassium. Use Caution/Monitor.
  
  aceclofenac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• acemetacin

  timolol and acemetacin both increase serum potassium. Use Caution/Monitor.
  
  acemetacin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• albuterol

  timolol increases and albuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of albuterol by pharmacodynamic antagonism. Use Caution/Monitor.

• aldesleukin

  aldesleukin increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• alfuzosin

  alfuzosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• aluminum hydroxide

  aluminum hydroxide decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• amifostine

  amifostine, brimonidine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.
  
  amifostine, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.

• amiloride

  timolol and amiloride both increase serum potassium. Modify Therapy/Monitor Closely.

• candesartan

  brimonidine increases effects of candesartan by pharmacodynamic synergism. Use Caution/Monitor.

• amiodarone

  amiodarone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  amiodarone, timolol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of cardiotoxicity with bradycardia.

• amlodipine

  timolol and amlodipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• amobarbital

  amobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of amobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• arformoterol

  timolol increases and arformoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of arformoterol by pharmacodynamic antagonism. Use Caution/Monitor.

• articaine

  timolol, articaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).

• asenapine

  asenapine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  asenapine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• aspirin

  timolol and aspirin both increase serum potassium. Use Caution/Monitor.
  
  aspirin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• aspirin rectal

  timolol and aspirin rectal both increase serum potassium. Use Caution/Monitor.
  
  aspirin rectal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• aspirin/citric acid/sodium bicarbonate

  aspirin/citric acid/sodium bicarbonate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and aspirin/citric acid/sodium bicarbonate both increase serum potassium. Use Caution/Monitor.

• atazanavir

  atazanavir increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of hypotension, bradycardia, AV block, and prolonged PR interval. Consider lowering beta blocker dose.

• atenolol

  atenolol and timolol both increase serum potassium. Use Caution/Monitor.

• avanafil

  avanafil increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• bendroflumethiazide

  timolol increases and bendroflumethiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• betaxolol

  betaxolol and timolol both increase serum potassium. Use Caution/Monitor.

• bismuth subsalicylate

  bismuth subsalicylate, timolol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Blockage of renal prostaglandin synthesis; may cause severe hypertension.

• bisoprolol

  bisoprolol and timolol both increase serum potassium. Use Caution/Monitor.

• bretylium

  timolol, bretylium. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Each drug may cause hypotension.

• bumetanide

  timolol increases and bumetanide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• bupivacaine

  timolol, bupivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• bupropion

  bupropion will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• butabarbital

  butabarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• butalbital

  butalbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• calcium acetate

  calcium acetate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium carbonate

  calcium carbonate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.
  
  calcium carbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• calcium chloride

  calcium chloride decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium citrate

  calcium citrate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium gluconate

  calcium gluconate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• candesartan

  candesartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, candesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

• carbenoxolone

  timolol increases and carbenoxolone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• carbidopa

  carbidopa increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.

• carvedilol

  carvedilol and timolol both increase serum potassium. Use Caution/Monitor.

• celecoxib

  celecoxib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  timolol and celecoxib both increase serum potassium. Use Caution/Monitor.
  
  celecoxib decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• celiprolol

  celiprolol and timolol both increase serum potassium. Use Caution/Monitor.

• chloroprocaine

  timolol, chloroprocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).

• chloroquine

  chloroquine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• chlorothiazide

  timolol increases and chlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• chlorpropamide

  timolol decreases effects of chlorpropamide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• chlorthalidone

  timolol increases and chlorthalidone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• choline magnesium trisalicylate

  timolol and choline magnesium trisalicylate both increase serum potassium. Use Caution/Monitor.
  
  choline magnesium trisalicylate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• cimetidine

  cimetidine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• citalopram

  citalopram increases levels of timolol by decreasing metabolism. Use Caution/Monitor.

• clevidipine

  timolol and clevidipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• clonidine

  timolol, clonidine. Mechanism: pharmacodynamic synergism. Modify Therapy/Monitor Closely. Non selective beta blocker administration during withdrawal from centrally acting alpha agonists may result in rebound hypertension.

• cobicistat

  cobicistat will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cyclopenthiazide

  timolol increases and cyclopenthiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• darifenacin

  darifenacin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• dasiglucagon

  timolol decreases effects of dasiglucagon by unknown mechanism. Use Caution/Monitor. Dasiglucagon may stimulate catecholamine release; whereas beta blockers may inhibit catecholamines released in response to dasiglucagon. Coadministration may also transiently increase pulse and BP.

• desflurane

  desflurane, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• desvenlafaxine

  desvenlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• diclofenac

  timolol and diclofenac both increase serum potassium. Use Caution/Monitor.
  
  diclofenac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• diflunisal

  timolol and diflunisal both increase serum potassium. Use Caution/Monitor.
  
  diflunisal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• digoxin

  timolol and digoxin both increase serum potassium. Use Caution/Monitor.
  
  timolol increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor. Enhanced bradycardia.
  
  brimonidine increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor.

• diltiazem

  timolol and diltiazem both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• eprosartan

  brimonidine increases effects of eprosartan by pharmacodynamic synergism. Use Caution/Monitor.

• diphenhydramine

  diphenhydramine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• dobutamine

  timolol increases and dobutamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of dobutamine by pharmacodynamic antagonism. Use Caution/Monitor.

• dopexamine

  timolol increases and dopexamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of dopexamine by pharmacodynamic antagonism. Use Caution/Monitor.

• doxazosin

  doxazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• dronedarone

  dronedarone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• drospirenone

  timolol and drospirenone both increase serum potassium. Modify Therapy/Monitor Closely.

• duloxetine

  duloxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• eliglustat

  eliglustat increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• ephedrine

  timolol increases and ephedrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of ephedrine by pharmacodynamic antagonism. Use Caution/Monitor.

• epinephrine

  timolol increases and epinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor.

• epinephrine inhaled

  timolol decreases effects of epinephrine inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Beta2-adrenergic blockers may may inhibit bronchodilatory effects of epinephrine.

• epinephrine racemic

  timolol increases and epinephrine racemic decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor.

• eprosartan

  eprosartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, eprosartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

• esketamine intranasal

  esketamine intranasal, brimonidine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• esmolol

  esmolol and timolol both increase serum potassium. Use Caution/Monitor.

• ethacrynic acid

  timolol increases and ethacrynic acid decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ether

  timolol, ether. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both beta blockers and ether depress the myocardium; consider lowering beta blocker dose if ether used for anesthesia.

• etodolac

  timolol and etodolac both increase serum potassium. Use Caution/Monitor.
  
  etodolac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• etomidate

  etomidate, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• fedratinib

  fedratinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• felodipine

  timolol and felodipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• fenbufen

  timolol and fenbufen both increase serum potassium. Use Caution/Monitor.

• fenoprofen

  timolol and fenoprofen both increase serum potassium. Use Caution/Monitor.
  
  fenoprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• fingolimod

  timolol increases effects of fingolimod by pharmacodynamic synergism. Use Caution/Monitor. Both medications decrease heart rate. Monitor patients on concomitant therapy, particularly in the first 6 hours after fingolimod is initiated or after a treatment interruption of at least two weeks, for bradycardia and atrioventricular block. To identify underlying risk factors of bradycardia and AV block, obtain a new or recent ECG in patients using beta-blockers prior to starting fingolimod.

• flurbiprofen

  timolol and flurbiprofen both increase serum potassium. Use Caution/Monitor.
  
  flurbiprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• formoterol

  timolol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.

• furosemide

  timolol increases and furosemide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• gentamicin

  timolol increases and gentamicin decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• glimepiride

  timolol decreases effects of glimepiride by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• glipizide

  timolol decreases effects of glipizide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• glucagon

  glucagon decreases toxicity of timolol by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Coadministration of glucagon with beta-blockers may have transiently increased pulse and blood pressure.

• glucagon intranasal

  glucagon intranasal decreases toxicity of timolol by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Coadministration of glucagon with beta-blockers may have transiently increased pulse and blood pressure.

• glyburide

  timolol decreases effects of glyburide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• guanfacine

  timolol, guanfacine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from centrally acting alpha agonists may result in rebound hypertension.

• haloperidol

  haloperidol will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• hydralazine

  hydralazine increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects.

• hydrochlorothiazide

  timolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ibuprofen

  timolol and ibuprofen both increase serum potassium. Use Caution/Monitor.
  
  ibuprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• ibuprofen IV

  ibuprofen IV decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ibuprofen IV both increase serum potassium. Use Caution/Monitor.

• imatinib

  imatinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• indacaterol, inhaled

  indacaterol, inhaled, timolol. Other (see comment). Use Caution/Monitor. Comment: Beta-blockers and indacaterol may interfere with the effect of each other when administered concurrently. Beta-blockers may produce severe bronchospasm in COPD patients. Therefore, patients with COPD should not normally be treated with beta-blockers. However, under certain circumstances, e.g. as prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta-blockers in patients with COPD. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

• indapamide

  timolol increases and indapamide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• indomethacin

  timolol and indomethacin both increase serum potassium. Use Caution/Monitor.
  
  indomethacin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• insulin aspart

  timolol, insulin aspart. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin degludec

  timolol, insulin degludec. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin degludec/insulin aspart

  timolol, insulin degludec/insulin aspart. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin detemir

  timolol, insulin detemir. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin glargine

  timolol, insulin glargine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin glulisine

  timolol, insulin glulisine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin inhaled

  timolol, insulin inhaled. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin lispro

  timolol, insulin lispro. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin NPH

  timolol, insulin NPH. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin regular human

  timolol, insulin regular human. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• irbesartan

  timolol, irbesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  irbesartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of irbesartan by pharmacodynamic synergism. Use Caution/Monitor.

• isoproterenol

  timolol increases and isoproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of isoproterenol by pharmacodynamic antagonism. Use Caution/Monitor.

• lasmiditan

  lasmiditan, brimonidine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• isradipine

  timolol and isradipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• ivabradine

  ivabradine, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Most patients receiving ivabradine will also be treated with a beta-blocker. The risk of bradycardia increases with coadministration of drugs that slow heart rate (eg, digoxin, amiodarone, beta-blockers). Monitor heart rate in patients taking ivabradine with other negative chronotropes.

• ketamine

  ketamine, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• ketoprofen

  timolol and ketoprofen both increase serum potassium. Use Caution/Monitor.
  
  ketoprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• ketorolac

  timolol and ketorolac both increase serum potassium. Use Caution/Monitor.
  
  ketorolac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• ketorolac intranasal

  timolol and ketorolac intranasal both increase serum potassium. Use Caution/Monitor.
  
  ketorolac intranasal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• labetalol

  labetalol and timolol both increase serum potassium. Use Caution/Monitor.

• lasmiditan

  timolol increases effects of lasmiditan by pharmacodynamic synergism. Use Caution/Monitor. Lasmiditan has been associated with a lowering of heart rate (HR). In a drug interaction study, addition of a single 200-mg dose of lasmiditan to propranolol decreased HR by an additional 5 bpm compared to propranolol alone, for a mean maximum of 19 bpm.

• levalbuterol

  timolol increases and levalbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of levalbuterol by pharmacodynamic antagonism. Use Caution/Monitor.

• levodopa

  levodopa increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.

• lidocaine

  timolol, lidocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).
  
  timolol increases levels of lidocaine by decreasing elimination. Use Caution/Monitor. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• lopinavir

  lopinavir increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of PR prolongation and cardiac arrhythmias. .

• lorcaserin

  lorcaserin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lornoxicam

  timolol and lornoxicam both increase serum potassium. Use Caution/Monitor.
  
  lornoxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• losartan

  losartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, losartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  brimonidine increases effects of losartan by pharmacodynamic synergism. Use Caution/Monitor.

• lurasidone

  lurasidone, brimonidine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased sedation.
  
  lurasidone increases effects of timolol by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.

• maraviroc

  maraviroc will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nitroglycerin rectal

  nitroglycerin rectal, brimonidine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .

• marijuana

  marijuana will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• meclofenamate

  meclofenamate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and meclofenamate both increase serum potassium. Use Caution/Monitor.

• mefenamic acid

  timolol and mefenamic acid both increase serum potassium. Use Caution/Monitor.
  
  mefenamic acid decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• mefloquine

  mefloquine increases levels of timolol by decreasing metabolism. Use Caution/Monitor. Risk of arrhythmia.

• meloxicam

  timolol and meloxicam both increase serum potassium. Use Caution/Monitor.
  
  meloxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• mepivacaine

  timolol, mepivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• metaproterenol

  timolol increases and metaproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of metaproterenol by pharmacodynamic antagonism. Use Caution/Monitor.

• methyclothiazide

  timolol increases and methyclothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

• methyldopa

  timolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension.

• methylphenidate

  methylphenidate will decrease the level or effect of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Methylphenidate may diminish antihypertensive effects. Monitor BP.

• metolazone

  timolol increases and metolazone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metoprolol

  metoprolol and timolol both increase serum potassium. Use Caution/Monitor.

• mirabegron

  mirabegron will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• moxisylyte

  moxisylyte and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nabumetone

  timolol and nabumetone both increase serum potassium. Use Caution/Monitor.
  
  nabumetone decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• nadolol

  nadolol and timolol both increase serum potassium. Use Caution/Monitor.

• naproxen

  timolol and naproxen both increase serum potassium. Use Caution/Monitor.
  
  naproxen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• nebivolol

  nebivolol and timolol both increase serum potassium. Use Caution/Monitor.

• nicardipine

  timolol and nicardipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nifedipine

  timolol and nifedipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nilotinib

  nilotinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nisoldipine

  timolol and nisoldipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• nitroglycerin rectal

  nitroglycerin rectal, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Beta-blockers blunt the reflex tachycardia produced by nitroglycerin without preventing its hypotensive effects. If beta-blockers are used with nitroglycerin in patients with angina pectoris, additional hypotensive effects may occur.

• norepinephrine

  timolol increases and norepinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of norepinephrine by pharmacodynamic antagonism. Use Caution/Monitor.

• olmesartan

  timolol, olmesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  brimonidine increases effects of olmesartan by pharmacodynamic synergism. Use Caution/Monitor.
  
  olmesartan and timolol both increase serum potassium. Use Caution/Monitor.

• olodaterol inhaled

  timolol, olodaterol inhaled. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor. Beta-blockers and olodaterol may interfere with the effect of each other when administered concurrently. Beta-blockers may produce severe bronchospasm in COPD patients. Therefore, patients with COPD should not normally be treated with beta-blockers. However, under certain circumstances, e.g. as prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta-blockers in patients with COPD. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

• sacubitril/valsartan

  brimonidine increases effects of sacubitril/valsartan by pharmacodynamic synergism. Use Caution/Monitor.

• oxaprozin

  timolol and oxaprozin both increase serum potassium. Use Caution/Monitor.
  
  oxaprozin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• oxymetazoline intranasal

  timolol increases effects of oxymetazoline intranasal by pharmacodynamic synergism. Use Caution/Monitor. When beta-2 receptors are antagonized by nonselective beta blockers, alpha1 vasoconstriction may be unopposed, thus increasing hypertensive effect. When oxymetazoline is combined with intranasal tetracaine for dental anesthesia, avoid or use an alternant anesthetic in patients taking nonselective beta blockers.

• oxymetazoline topical

  oxymetazoline topical increases and timolol decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• parecoxib

  parecoxib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  timolol and parecoxib both increase serum potassium. Use Caution/Monitor.
  
  parecoxib decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• peginterferon alfa 2b

  peginterferon alfa 2b, timolol. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• penbutolol

  penbutolol and timolol both increase serum potassium. Use Caution/Monitor.

• pentobarbital

  pentobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of pentobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• perphenazine

  perphenazine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• phenobarbital

  phenobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of phenobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• phenoxybenzamine

  phenoxybenzamine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• phentolamine

  phentolamine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• phenylephrine

  timolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

• phenylephrine PO

  timolol increases effects of phenylephrine PO by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

• pindolol

  pindolol and timolol both increase serum potassium. Use Caution/Monitor.

• pirbuterol

  timolol increases and pirbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of pirbuterol by pharmacodynamic antagonism. Use Caution/Monitor.

• piroxicam

  timolol and piroxicam both increase serum potassium. Use Caution/Monitor.
  
  piroxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• ponesimod

  ponesimod and timolol both increase pharmacodynamic synergism. Use Caution/Monitor. Beta-blockers may have additive effects on lowering HR. Consider resting HR before initiating ponesimod in patients on stable dose of beta-blocker. Refer to the ponesimod prescribing information for more dosing information.

• potassium acid phosphate

  timolol and potassium acid phosphate both increase serum potassium. Modify Therapy/Monitor Closely.

• potassium chloride

  timolol and potassium chloride both increase serum potassium. Modify Therapy/Monitor Closely.

• potassium citrate

  timolol and potassium citrate both increase serum potassium. Modify Therapy/Monitor Closely.

• prazosin

  prazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• prilocaine

  timolol, prilocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• primidone

  primidone decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of primidone. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• propafenone

  propafenone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propofol

  propofol, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• propranolol

  propranolol and timolol both increase serum potassium. Use Caution/Monitor.

• quinacrine

  quinacrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• ranolazine

  ranolazine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• ritonavir

  ritonavir increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of hypotension, bradycardia, AV block, and prolonged PR interval. Consider lowering beta blocker dose.

• rolapitant

  rolapitant will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• ropivacaine

  timolol, ropivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• sacubitril/valsartan

  sacubitril/valsartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, sacubitril/valsartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

• salicylates (non-asa)

  timolol and salicylates (non-asa) both increase serum potassium. Use Caution/Monitor.
  
  salicylates (non-asa) decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• salmeterol

  timolol increases and salmeterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  timolol decreases effects of salmeterol by pharmacodynamic antagonism. Use Caution/Monitor.

• salsalate

  timolol and salsalate both increase serum potassium. Use Caution/Monitor.
  
  salsalate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• saquinavir

  saquinavir, timolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• secobarbital

  secobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of secobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.

• sertraline

  sertraline will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• sevoflurane

  sevoflurane, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• sildenafil

  timolol increases effects of sildenafil by additive vasodilation. Use Caution/Monitor. Sildenafil has systemic vasodilatory properties and may further lower blood pressure in patients taking antihypertensive medications. Monitor blood pressure response to sildenafil in patients receiving concurrent blood pressure lowering therapy.

• silodosin

  silodosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• siponimod

  siponimod, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• sodium bicarbonate

  sodium bicarbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sodium citrate/citric acid

  sodium citrate/citric acid decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sotalol

  sotalol and timolol both increase serum potassium. Use Caution/Monitor.

• spironolactone

  timolol and spironolactone both increase serum potassium. Modify Therapy/Monitor Closely.

• stiripentol

  stiripentol, brimonidine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• succinylcholine

  timolol and succinylcholine both increase serum potassium. Use Caution/Monitor.

• sulfasalazine

  timolol and sulfasalazine both increase serum potassium. Use Caution/Monitor.
  
  sulfasalazine decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• sulindac

  timolol and sulindac both increase serum potassium. Use Caution/Monitor.
  
  sulindac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

• tadalafil

  tadalafil increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• telmisartan

  timolol, telmisartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  telmisartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of telmisartan by pharmacodynamic synergism. Use Caution/Monitor.

• terazosin

  terazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

• valsartan

  brimonidine increases effects of valsartan by pharmacodynamic synergism. Use Caution/Monitor.

Minor (195)

• acebutolol

  brimonidine increases effects of acebutolol by pharmacodynamic synergism. Minor/Significance Unknown.

• adenosine

  timolol, adenosine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Bradycardia.

• agrimony

  agrimony increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• alfentanil

  brimonidine increases effects of alfentanil by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• alfuzosin

  brimonidine increases effects of alfuzosin by pharmacodynamic synergism. Minor/Significance Unknown.

• alprazolam

  brimonidine increases effects of alprazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• amiloride

  brimonidine increases effects of amiloride by pharmacodynamic synergism. Minor/Significance Unknown.

• amitriptyline

  amitriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• amlodipine

  brimonidine increases effects of amlodipine by pharmacodynamic synergism. Minor/Significance Unknown.

• amobarbital

  brimonidine increases effects of amobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• amoxapine

  amoxapine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• aripiprazole

  brimonidine increases effects of aripiprazole by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• asenapine

  brimonidine increases effects of asenapine by pharmacodynamic synergism. Minor/Significance Unknown.

• atenolol

  brimonidine increases effects of atenolol by pharmacodynamic synergism. Minor/Significance Unknown.

• azelastine

  brimonidine increases effects of azelastine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• belladonna and opium

  brimonidine increases effects of belladonna and opium by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• benazepril

  brimonidine increases effects of benazepril by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.

• bendroflumethiazide

  brimonidine increases effects of bendroflumethiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• benperidol

  brimonidine increases effects of benperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• betaxolol

  brimonidine increases effects of betaxolol by pharmacodynamic synergism. Minor/Significance Unknown.

• bisoprolol

  brimonidine increases effects of bisoprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• bosentan

  brimonidine increases effects of bosentan by pharmacodynamic synergism. Minor/Significance Unknown.

• brimonidine

  brimonidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• brompheniramine

  brimonidine increases effects of brompheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• bumetanide

  brimonidine increases effects of bumetanide by pharmacodynamic synergism. Minor/Significance Unknown.

• buprenorphine

  brimonidine increases effects of buprenorphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• buprenorphine buccal

  brimonidine increases effects of buprenorphine buccal by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butabarbital

  brimonidine increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butalbital

  brimonidine increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butorphanol

  brimonidine increases effects of butorphanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• captopril

  brimonidine increases effects of captopril by pharmacodynamic synergism. Minor/Significance Unknown. Both drugs lower blood pressure. Monitor blood pressure.

• carbinoxamine

  brimonidine increases effects of carbinoxamine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• carvedilol

  brimonidine increases effects of carvedilol by pharmacodynamic synergism. Minor/Significance Unknown.

• celiprolol

  brimonidine increases effects of celiprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• cevimeline

  cevimeline increases effects of timolol by unspecified interaction mechanism. Minor/Significance Unknown.

• chloral hydrate

  brimonidine increases effects of chloral hydrate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlordiazepoxide

  brimonidine increases effects of chlordiazepoxide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlorothiazide

  brimonidine increases effects of chlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• chlorpheniramine

  brimonidine increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlorpromazine

  brimonidine increases effects of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlorthalidone

  brimonidine increases effects of chlorthalidone by pharmacodynamic synergism. Minor/Significance Unknown.

• cinnarizine

  brimonidine increases effects of cinnarizine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ciprofloxacin

  ciprofloxacin increases levels of timolol by decreasing metabolism. Minor/Significance Unknown. May also rarely decrease beta blocker levels.

• clemastine

  brimonidine increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clevidipine

  brimonidine increases effects of clevidipine by pharmacodynamic synergism. Minor/Significance Unknown.

• clomipramine

  clomipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• clonazepam

  brimonidine increases effects of clonazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clonidine

  brimonidine increases effects of clonidine by pharmacodynamic synergism. Minor/Significance Unknown.

• clorazepate

  brimonidine increases effects of clorazepate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clozapine

  brimonidine increases effects of clozapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cocaine topical

  timolol increases effects of cocaine topical by pharmacodynamic synergism. Minor/Significance Unknown. Risk of angina.

• codeine

  brimonidine increases effects of codeine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cornsilk

  cornsilk increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• cyclizine

  brimonidine increases effects of cyclizine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cyclopenthiazide

  brimonidine increases effects of cyclopenthiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• cyproheptadine

  brimonidine increases effects of cyproheptadine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• desipramine

  desipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• dexchlorpheniramine

  brimonidine increases effects of dexchlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dexmedetomidine

  brimonidine increases effects of dexmedetomidine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dextromoramide

  brimonidine increases effects of dextromoramide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diamorphine

  brimonidine increases effects of diamorphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diazepam

  brimonidine increases effects of diazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• difenoxin hcl

  brimonidine increases effects of difenoxin hcl by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dihydroergotamine

  dihydroergotamine, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive vasospasm.

• dihydroergotamine intranasal

  dihydroergotamine intranasal, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive vasospasm.

• diltiazem

  brimonidine increases effects of diltiazem by pharmacodynamic synergism. Minor/Significance Unknown.

• dimenhydrinate

  brimonidine increases effects of dimenhydrinate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diphenhydramine

  brimonidine increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diphenoxylate hcl

  brimonidine increases effects of diphenoxylate hcl by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dipipanone

  brimonidine increases effects of dipipanone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dipyridamole

  dipyridamole, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of bradycardia.

• doxazosin

  brimonidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• doxepin

  doxepin decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• doxylamine

  brimonidine increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• droperidol

  brimonidine increases effects of droperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• drospirenone

  brimonidine increases effects of drospirenone by pharmacodynamic synergism. Minor/Significance Unknown.

• enalapril

  brimonidine increases effects of enalapril by pharmacodynamic synergism. Minor/Significance Unknown.

• eplerenone

  brimonidine increases effects of eplerenone by pharmacodynamic synergism. Minor/Significance Unknown.

• epoprostenol

  brimonidine increases effects of epoprostenol by pharmacodynamic synergism. Minor/Significance Unknown.

• escitalopram

  escitalopram increases levels of timolol by decreasing metabolism. Minor/Significance Unknown.

• esmolol

  brimonidine increases effects of esmolol by pharmacodynamic synergism. Minor/Significance Unknown.

• estazolam

  brimonidine increases effects of estazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ethacrynic acid

  brimonidine increases effects of ethacrynic acid by pharmacodynamic synergism. Minor/Significance Unknown.

• ethanol

  brimonidine increases effects of ethanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• etomidate

  brimonidine increases effects of etomidate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• felodipine

  brimonidine increases effects of felodipine by pharmacodynamic synergism. Minor/Significance Unknown.

• fenoldopam

  fenoldopam increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  brimonidine increases effects of fenoldopam by pharmacodynamic synergism. Minor/Significance Unknown.

• fluphenazine

  brimonidine increases effects of fluphenazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• forskolin

  forskolin increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• flurazepam

  brimonidine increases effects of flurazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• fosinopril

  brimonidine increases effects of fosinopril by pharmacodynamic synergism. Minor/Significance Unknown.

• furosemide

  brimonidine increases effects of furosemide by pharmacodynamic synergism. Minor/Significance Unknown.

• guanfacine

  brimonidine increases effects of guanfacine by pharmacodynamic synergism. Minor/Significance Unknown.

• haloperidol

  brimonidine increases effects of haloperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• hydralazine

  brimonidine increases effects of hydralazine by pharmacodynamic synergism. Minor/Significance Unknown.

• hydrochlorothiazide

  brimonidine increases effects of hydrochlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• hydromorphone

  brimonidine increases effects of hydromorphone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• hydroxyzine

  brimonidine increases effects of hydroxyzine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• iloperidone

  brimonidine increases effects of iloperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• iloprost

  brimonidine increases effects of iloprost by pharmacodynamic synergism. Minor/Significance Unknown.

• imaging agents (gadolinium)

  timolol, imaging agents (gadolinium). Mechanism: unknown. Minor/Significance Unknown. Increased risk of anaphylaxis from contrast media.

• imidapril

  brimonidine increases effects of imidapril by pharmacodynamic synergism. Minor/Significance Unknown.

• imipramine

  imipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• indapamide

  brimonidine increases effects of indapamide by pharmacodynamic synergism. Minor/Significance Unknown.

• isradipine

  brimonidine increases effects of isradipine by pharmacodynamic synergism. Minor/Significance Unknown.

• ketanserin

  brimonidine increases effects of ketanserin by pharmacodynamic synergism. Minor/Significance Unknown.

• labetalol

  brimonidine increases effects of labetalol by pharmacodynamic synergism. Minor/Significance Unknown.

• levobetaxolol

  levobetaxolol increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• levorphanol

  brimonidine increases effects of levorphanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lisinopril

  brimonidine increases effects of lisinopril by pharmacodynamic synergism. Minor/Significance Unknown.

• lofepramine

  lofepramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• loprazolam

  brimonidine increases effects of loprazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lorazepam

  brimonidine increases effects of lorazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lormetazepam

  brimonidine increases effects of lormetazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• loxapine

  brimonidine increases effects of loxapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• loxapine inhaled

  brimonidine increases effects of loxapine inhaled by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• maitake

  maitake increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• maprotiline

  maprotiline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• mecamylamine

  brimonidine increases effects of mecamylamine by pharmacodynamic synergism. Minor/Significance Unknown.

• melatonin

  melatonin decreases toxicity of timolol by pharmacodynamic antagonism. Minor/Significance Unknown. Melatonin may correct beta blocker induced sleep disturbances.

• meperidine

  brimonidine increases effects of meperidine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• meprobamate

  brimonidine increases effects of meprobamate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• methadone

  brimonidine increases effects of methadone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• methyclothiazide

  brimonidine increases effects of methyclothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• metipranolol ophthalmic

  metipranolol ophthalmic increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• metolazone

  brimonidine increases effects of metolazone by pharmacodynamic synergism. Minor/Significance Unknown.

• metoprolol

  brimonidine increases effects of metoprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• metyrosine

  brimonidine increases effects of metyrosine by pharmacodynamic synergism. Minor/Significance Unknown.

• midazolam

  brimonidine increases effects of midazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• minoxidil

  brimonidine increases effects of minoxidil by pharmacodynamic synergism. Minor/Significance Unknown.

• moexipril

  brimonidine increases effects of moexipril by pharmacodynamic synergism. Minor/Significance Unknown.

• morphine

  brimonidine increases effects of morphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• moxisylyte

  brimonidine increases effects of moxisylyte by pharmacodynamic synergism. Minor/Significance Unknown.

• moxonidine

  brimonidine increases effects of moxonidine by pharmacodynamic synergism. Minor/Significance Unknown.

• nadolol

  brimonidine increases effects of nadolol by pharmacodynamic synergism. Minor/Significance Unknown.

• nalbuphine

  brimonidine increases effects of nalbuphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• nebivolol

  brimonidine increases effects of nebivolol by pharmacodynamic synergism. Minor/Significance Unknown.

• neostigmine

  timolol, neostigmine. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive bradycardia.

• nicardipine

  brimonidine increases effects of nicardipine by pharmacodynamic synergism. Minor/Significance Unknown.

• nifedipine

  brimonidine increases effects of nifedipine by pharmacodynamic synergism. Minor/Significance Unknown.

• nisoldipine

  brimonidine increases effects of nisoldipine by pharmacodynamic synergism. Minor/Significance Unknown.

• noni juice

  timolol and noni juice both increase serum potassium. Minor/Significance Unknown.

• nortriptyline

  nortriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• octacosanol

  octacosanol increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• olanzapine

  brimonidine increases effects of olanzapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• opium tincture

  brimonidine increases effects of opium tincture by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxazepam

  brimonidine increases effects of oxazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxycodone

  brimonidine increases effects of oxycodone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxymorphone

  brimonidine increases effects of oxymorphone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• paliperidone

  brimonidine increases effects of paliperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• papaveretum

  brimonidine increases effects of papaveretum by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• penbutolol

  brimonidine increases effects of penbutolol by pharmacodynamic synergism. Minor/Significance Unknown.

• pentazocine

  brimonidine increases effects of pentazocine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• pentobarbital

  brimonidine increases effects of pentobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• perindopril

  brimonidine increases effects of perindopril by pharmacodynamic synergism. Minor/Significance Unknown.

• perphenazine

  brimonidine increases effects of perphenazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• phenobarbital

  brimonidine increases effects of phenobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• phenoxybenzamine

  brimonidine increases effects of phenoxybenzamine by pharmacodynamic synergism. Minor/Significance Unknown.

• phentolamine

  brimonidine increases effects of phentolamine by pharmacodynamic synergism. Minor/Significance Unknown.

• physostigmine

  timolol, physostigmine. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive bradycardia.

• pilocarpine

  pilocarpine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• pimozide

  brimonidine increases effects of pimozide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• pindolol

  brimonidine increases effects of pindolol by pharmacodynamic synergism. Minor/Significance Unknown.

• prazosin

  brimonidine increases effects of prazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• primidone

  brimonidine increases effects of primidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• prochlorperazine

  brimonidine increases effects of prochlorperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• promethazine

  brimonidine increases effects of promethazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• propranolol

  brimonidine increases effects of propranolol by pharmacodynamic synergism. Minor/Significance Unknown.

• protriptyline

  protriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• quazepam

  brimonidine increases effects of quazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• quetiapine

  brimonidine increases effects of quetiapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• quinapril

  brimonidine increases effects of quinapril by pharmacodynamic synergism. Minor/Significance Unknown.

• ramipril

  brimonidine increases effects of ramipril by pharmacodynamic synergism. Minor/Significance Unknown.

• reishi

  reishi increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• risperidone

  brimonidine increases effects of risperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• secobarbital

  brimonidine increases effects of secobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• shepherd's purse

  shepherd's purse, timolol. Other (see comment). Minor/Significance Unknown. Comment: Theoretically, shepherd's purse may interfere with BP control.

• silodosin

  brimonidine increases effects of silodosin by pharmacodynamic synergism. Minor/Significance Unknown.

• sotalol

  brimonidine increases effects of sotalol by pharmacodynamic synergism. Minor/Significance Unknown.

• spironolactone

  brimonidine increases effects of spironolactone by pharmacodynamic synergism. Minor/Significance Unknown.

• sufentanil

  brimonidine increases effects of sufentanil by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• tapentadol

  brimonidine increases effects of tapentadol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• temazepam

  brimonidine increases effects of temazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• terazosin

  brimonidine increases effects of terazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• thioridazine

  brimonidine increases effects of thioridazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• thiothixene

  brimonidine increases effects of thiothixene by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• timolol

  brimonidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• tizanidine

  tizanidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.

• torsemide

  brimonidine increases effects of torsemide by pharmacodynamic synergism. Minor/Significance Unknown.

• tramadol

  brimonidine increases effects of tramadol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• trandolapril

  brimonidine increases effects of trandolapril by pharmacodynamic synergism. Minor/Significance Unknown.

• trazodone

  trazodone decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• treprostinil

  treprostinil increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.
  
  brimonidine increases effects of treprostinil by pharmacodynamic synergism. Minor/Significance Unknown.

• triamterene

  brimonidine increases effects of triamterene by pharmacodynamic synergism. Minor/Significance Unknown.

• yohimbe

  timolol decreases toxicity of yohimbe by pharmacodynamic antagonism. Minor/Significance Unknown.

• acebutolol

  Monitor Closely (1)acebutolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)acebutolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of acebutolol by pharmacodynamic synergism. Minor/Significance Unknown.

• aceclofenac

  Monitor Closely (2)aceclofenac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and aceclofenac both increase serum potassium. Use Caution/Monitor.

• acemetacin

  Monitor Closely (2)acemetacin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and acemetacin both increase serum potassium. Use Caution/Monitor.

• adenosine

  Minor (1)timolol, adenosine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Bradycardia.

• agrimony

  Minor (1)agrimony increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• albuterol

  Monitor Closely (2)timolol decreases effects of albuterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and albuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aldesleukin

  Monitor Closely (1)aldesleukin increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• alfentanil

  Minor (1)brimonidine increases effects of alfentanil by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• alfuzosin

  Monitor Closely (1)alfuzosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of alfuzosin by pharmacodynamic synergism. Minor/Significance Unknown.

• alprazolam

  Minor (1)brimonidine increases effects of alprazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• aluminum hydroxide

  Monitor Closely (1)aluminum hydroxide decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• amifostine

  Monitor Closely (2)amifostine, brimonidine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.
  
  amifostine, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.

• amiloride

  Monitor Closely (1)timolol and amiloride both increase serum potassium. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of amiloride by pharmacodynamic synergism. Minor/Significance Unknown.

• amiodarone

  Monitor Closely (2)amiodarone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  amiodarone, timolol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of cardiotoxicity with bradycardia.

• amitriptyline

  Minor (1)amitriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• amlodipine

  Monitor Closely (1)timolol and amlodipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of amlodipine by pharmacodynamic synergism. Minor/Significance Unknown.

• amobarbital

  Monitor Closely (1)amobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of amobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of amobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• amoxapine

  Minor (1)amoxapine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• arformoterol

  Monitor Closely (2)timolol decreases effects of arformoterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and arformoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  Minor (1)brimonidine increases effects of aripiprazole by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• artemether/lumefantrine

  Serious - Use Alternative (1)artemether/lumefantrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• articaine

  Monitor Closely (1)timolol, articaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).

• asenapine

  Monitor Closely (2)asenapine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  asenapine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of asenapine by pharmacodynamic synergism. Minor/Significance Unknown.

• aspirin

  Monitor Closely (2)aspirin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and aspirin both increase serum potassium. Use Caution/Monitor.

• aspirin rectal

  Monitor Closely (2)aspirin rectal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and aspirin rectal both increase serum potassium. Use Caution/Monitor.

• aspirin/citric acid/sodium bicarbonate

  Monitor Closely (2)aspirin/citric acid/sodium bicarbonate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and aspirin/citric acid/sodium bicarbonate both increase serum potassium. Use Caution/Monitor.

• atazanavir

  Monitor Closely (1)atazanavir increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of hypotension, bradycardia, AV block, and prolonged PR interval. Consider lowering beta blocker dose.

• atenolol

  Monitor Closely (1)atenolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)atenolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of atenolol by pharmacodynamic synergism. Minor/Significance Unknown.

• avanafil

  Monitor Closely (1)avanafil increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• azelastine

  Minor (1)brimonidine increases effects of azelastine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• belladonna and opium

  Minor (1)brimonidine increases effects of belladonna and opium by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• benazepril

  Minor (1)brimonidine increases effects of benazepril by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.

• bendroflumethiazide

  Monitor Closely (1)timolol increases and bendroflumethiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of bendroflumethiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• benperidol

  Minor (1)brimonidine increases effects of benperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• betaxolol

  Monitor Closely (1)betaxolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)betaxolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of betaxolol by pharmacodynamic synergism. Minor/Significance Unknown.

• bismuth subsalicylate

  Monitor Closely (1)bismuth subsalicylate, timolol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Blockage of renal prostaglandin synthesis; may cause severe hypertension.

• bisoprolol

  Monitor Closely (1)bisoprolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)bisoprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of bisoprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• bosentan

  Minor (1)brimonidine increases effects of bosentan by pharmacodynamic synergism. Minor/Significance Unknown.

• bretylium

  Monitor Closely (1)timolol, bretylium. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Each drug may cause hypotension.

• brimonidine

  Minor (1)brimonidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• brompheniramine

  Minor (1)brimonidine increases effects of brompheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• bumetanide

  Monitor Closely (1)timolol increases and bumetanide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of bumetanide by pharmacodynamic synergism. Minor/Significance Unknown.

• bupivacaine

  Monitor Closely (1)timolol, bupivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• buprenorphine

  Minor (1)brimonidine increases effects of buprenorphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• buprenorphine buccal

  Minor (1)brimonidine increases effects of buprenorphine buccal by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• bupropion

  Monitor Closely (1)bupropion will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• butabarbital

  Monitor Closely (1)butabarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butabarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of butabarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butalbital

  Monitor Closely (1)butalbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of butalbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of butalbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butorphanol

  Minor (1)brimonidine increases effects of butorphanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• calcium acetate

  Monitor Closely (1)calcium acetate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium carbonate

  Monitor Closely (2)calcium carbonate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.
  
  calcium carbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• calcium chloride

  Monitor Closely (1)calcium chloride decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium citrate

  Monitor Closely (1)calcium citrate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• calcium gluconate

  Monitor Closely (1)calcium gluconate decreases effects of timolol by unspecified interaction mechanism. Use Caution/Monitor.

• candesartan

  Monitor Closely (3)timolol, candesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  candesartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of candesartan by pharmacodynamic synergism. Use Caution/Monitor.

• captopril

  Minor (1)brimonidine increases effects of captopril by pharmacodynamic synergism. Minor/Significance Unknown. Both drugs lower blood pressure. Monitor blood pressure.

• carbenoxolone

  Monitor Closely (1)timolol increases and carbenoxolone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• carbidopa

  Monitor Closely (1)carbidopa increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.

• carbinoxamine

  Minor (1)brimonidine increases effects of carbinoxamine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• carvedilol

  Monitor Closely (1)carvedilol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)carvedilol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of carvedilol by pharmacodynamic synergism. Minor/Significance Unknown.

• celecoxib

  Monitor Closely (3)celecoxib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  celecoxib decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and celecoxib both increase serum potassium. Use Caution/Monitor.

• celiprolol

  Monitor Closely (1)celiprolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)celiprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of celiprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• cevimeline

  Minor (1)cevimeline increases effects of timolol by unspecified interaction mechanism. Minor/Significance Unknown.

• chloral hydrate

  Minor (1)brimonidine increases effects of chloral hydrate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlordiazepoxide

  Minor (1)brimonidine increases effects of chlordiazepoxide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chloroprocaine

  Monitor Closely (1)timolol, chloroprocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).

• chloroquine

  Monitor Closely (1)chloroquine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• chlorothiazide

  Monitor Closely (1)timolol increases and chlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of chlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• chlorpheniramine

  Minor (1)brimonidine increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlorpromazine

  Minor (1)brimonidine increases effects of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• chlorpropamide

  Monitor Closely (1)timolol decreases effects of chlorpropamide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• chlorthalidone

  Monitor Closely (1)timolol increases and chlorthalidone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of chlorthalidone by pharmacodynamic synergism. Minor/Significance Unknown.

• choline magnesium trisalicylate

  Monitor Closely (2)choline magnesium trisalicylate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and choline magnesium trisalicylate both increase serum potassium. Use Caution/Monitor.

• cimetidine

  Monitor Closely (1)cimetidine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cinnarizine

  Minor (1)brimonidine increases effects of cinnarizine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ciprofloxacin

  Minor (1)ciprofloxacin increases levels of timolol by decreasing metabolism. Minor/Significance Unknown. May also rarely decrease beta blocker levels.

• citalopram

  Monitor Closely (1)citalopram increases levels of timolol by decreasing metabolism. Use Caution/Monitor.

• clemastine

  Minor (1)brimonidine increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clevidipine

  Monitor Closely (1)timolol and clevidipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of clevidipine by pharmacodynamic synergism. Minor/Significance Unknown.

• clomipramine

  Minor (1)clomipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• clonazepam

  Minor (1)brimonidine increases effects of clonazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clonidine

  Monitor Closely (1)timolol, clonidine. Mechanism: pharmacodynamic synergism. Modify Therapy/Monitor Closely. Non selective beta blocker administration during withdrawal from centrally acting alpha agonists may result in rebound hypertension.Serious - Use Alternative (1)clonidine, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.Minor (1)brimonidine increases effects of clonidine by pharmacodynamic synergism. Minor/Significance Unknown.

• clorazepate

  Minor (1)brimonidine increases effects of clorazepate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• clozapine

  Minor (1)brimonidine increases effects of clozapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cobicistat

  Monitor Closely (1)cobicistat will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cocaine topical

  Minor (1)timolol increases effects of cocaine topical by pharmacodynamic synergism. Minor/Significance Unknown. Risk of angina.

• codeine

  Minor (1)brimonidine increases effects of codeine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cornsilk

  Minor (1)cornsilk increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• cyclizine

  Minor (1)brimonidine increases effects of cyclizine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• cyclopenthiazide

  Monitor Closely (1)timolol increases and cyclopenthiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of cyclopenthiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• cyproheptadine

  Minor (1)brimonidine increases effects of cyproheptadine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dacomitinib

  Serious - Use Alternative (1)dacomitinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• darifenacin

  Monitor Closely (1)darifenacin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• dasiglucagon

  Monitor Closely (1)timolol decreases effects of dasiglucagon by unknown mechanism. Use Caution/Monitor. Dasiglucagon may stimulate catecholamine release; whereas beta blockers may inhibit catecholamines released in response to dasiglucagon. Coadministration may also transiently increase pulse and BP.

• desflurane

  Monitor Closely (1)desflurane, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• desipramine

  Minor (1)desipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• desvenlafaxine

  Monitor Closely (1)desvenlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• dexchlorpheniramine

  Minor (1)brimonidine increases effects of dexchlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dexmedetomidine

  Minor (1)brimonidine increases effects of dexmedetomidine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dextromoramide

  Minor (1)brimonidine increases effects of dextromoramide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diamorphine

  Minor (1)brimonidine increases effects of diamorphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diazepam

  Minor (1)brimonidine increases effects of diazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diclofenac

  Monitor Closely (2)diclofenac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and diclofenac both increase serum potassium. Use Caution/Monitor.

• difenoxin hcl

  Minor (1)brimonidine increases effects of difenoxin hcl by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diflunisal

  Monitor Closely (2)diflunisal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and diflunisal both increase serum potassium. Use Caution/Monitor.

• digoxin

  Monitor Closely (3)timolol increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor. Enhanced bradycardia.
  
  timolol and digoxin both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor.Serious - Use Alternative (1)digoxin, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

• dihydroergotamine

  Minor (1)dihydroergotamine, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive vasospasm.

• dihydroergotamine intranasal

  Minor (1)dihydroergotamine intranasal, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive vasospasm.

• diltiazem

  Monitor Closely (1)timolol and diltiazem both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)diltiazem, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.Minor (1)brimonidine increases effects of diltiazem by pharmacodynamic synergism. Minor/Significance Unknown.

• dimenhydrinate

  Minor (1)brimonidine increases effects of dimenhydrinate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diphenhydramine

  Monitor Closely (1)diphenhydramine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)brimonidine increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• diphenoxylate hcl

  Minor (1)brimonidine increases effects of diphenoxylate hcl by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dipipanone

  Minor (1)brimonidine increases effects of dipipanone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dipyridamole

  Minor (1)dipyridamole, timolol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of bradycardia.

• dobutamine

  Monitor Closely (2)timolol decreases effects of dobutamine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and dobutamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dopexamine

  Monitor Closely (2)timolol decreases effects of dopexamine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and dopexamine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• doxazosin

  Monitor Closely (1)doxazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• doxepin

  Minor (1)doxepin decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• doxylamine

  Minor (1)brimonidine increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• dronedarone

  Monitor Closely (1)dronedarone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• droperidol

  Minor (1)brimonidine increases effects of droperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• drospirenone

  Monitor Closely (1)timolol and drospirenone both increase serum potassium. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of drospirenone by pharmacodynamic synergism. Minor/Significance Unknown.

• duloxetine

  Monitor Closely (1)duloxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• eliglustat

  Monitor Closely (1)eliglustat increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Monitor Closely (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• enalapril

  Minor (1)brimonidine increases effects of enalapril by pharmacodynamic synergism. Minor/Significance Unknown.

• ephedrine

  Monitor Closely (2)timolol decreases effects of ephedrine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and ephedrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine

  Monitor Closely (2)timolol decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and epinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)timolol increases effects of epinephrine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• epinephrine inhaled

  Monitor Closely (1)timolol decreases effects of epinephrine inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Beta2-adrenergic blockers may may inhibit bronchodilatory effects of epinephrine.

• epinephrine racemic

  Monitor Closely (2)timolol decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and epinephrine racemic decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)timolol increases effects of epinephrine racemic by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• eplerenone

  Minor (1)brimonidine increases effects of eplerenone by pharmacodynamic synergism. Minor/Significance Unknown.

• epoprostenol

  Minor (1)brimonidine increases effects of epoprostenol by pharmacodynamic synergism. Minor/Significance Unknown.

• eprosartan

  Monitor Closely (3)timolol, eprosartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  eprosartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of eprosartan by pharmacodynamic synergism. Use Caution/Monitor.

• escitalopram

  Minor (1)escitalopram increases levels of timolol by decreasing metabolism. Minor/Significance Unknown.

• esketamine intranasal

  Monitor Closely (1)esketamine intranasal, brimonidine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• esmolol

  Monitor Closely (1)esmolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)esmolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of esmolol by pharmacodynamic synergism. Minor/Significance Unknown.

• estazolam

  Minor (1)brimonidine increases effects of estazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ethacrynic acid

  Monitor Closely (1)timolol increases and ethacrynic acid decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of ethacrynic acid by pharmacodynamic synergism. Minor/Significance Unknown.

• ethanol

  Minor (1)brimonidine increases effects of ethanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ether

  Monitor Closely (1)timolol, ether. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both beta blockers and ether depress the myocardium; consider lowering beta blocker dose if ether used for anesthesia.

• etodolac

  Monitor Closely (2)etodolac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and etodolac both increase serum potassium. Use Caution/Monitor.

• etomidate

  Monitor Closely (1)etomidate, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.Minor (1)brimonidine increases effects of etomidate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• felodipine

  Monitor Closely (1)timolol and felodipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of felodipine by pharmacodynamic synergism. Minor/Significance Unknown.

• fenbufen

  Monitor Closely (1)timolol and fenbufen both increase serum potassium. Use Caution/Monitor.

• fenoldopam

  Minor (2)fenoldopam increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  brimonidine increases effects of fenoldopam by pharmacodynamic synergism. Minor/Significance Unknown.

• fenoprofen

  Monitor Closely (2)fenoprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and fenoprofen both increase serum potassium. Use Caution/Monitor.

• fexinidazole

  Serious - Use Alternative (1)fexinidazole, timolol. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to induce bradycardia. .

• fingolimod

  Monitor Closely (1)timolol increases effects of fingolimod by pharmacodynamic synergism. Use Caution/Monitor. Both medications decrease heart rate. Monitor patients on concomitant therapy, particularly in the first 6 hours after fingolimod is initiated or after a treatment interruption of at least two weeks, for bradycardia and atrioventricular block. To identify underlying risk factors of bradycardia and AV block, obtain a new or recent ECG in patients using beta-blockers prior to starting fingolimod.

• fluoxetine

  Serious - Use Alternative (1)fluoxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• fluphenazine

  Minor (1)brimonidine increases effects of fluphenazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• flurazepam

  Minor (1)brimonidine increases effects of flurazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• flurbiprofen

  Monitor Closely (2)flurbiprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and flurbiprofen both increase serum potassium. Use Caution/Monitor.

• formoterol

  Monitor Closely (2)timolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• forskolin

  Minor (1)forskolin increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• fosinopril

  Minor (1)brimonidine increases effects of fosinopril by pharmacodynamic synergism. Minor/Significance Unknown.

• furosemide

  Monitor Closely (1)timolol increases and furosemide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of furosemide by pharmacodynamic synergism. Minor/Significance Unknown.

• gentamicin

  Monitor Closely (1)timolol increases and gentamicin decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• givosiran

  Serious - Use Alternative (1)givosiran will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• glimepiride

  Monitor Closely (1)timolol decreases effects of glimepiride by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• glipizide

  Monitor Closely (1)timolol decreases effects of glipizide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• glucagon

  Monitor Closely (1)glucagon decreases toxicity of timolol by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Coadministration of glucagon with beta-blockers may have transiently increased pulse and blood pressure.

• glucagon intranasal

  Monitor Closely (1)glucagon intranasal decreases toxicity of timolol by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Coadministration of glucagon with beta-blockers may have transiently increased pulse and blood pressure.

• glyburide

  Monitor Closely (1)timolol decreases effects of glyburide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• guanfacine

  Monitor Closely (1)timolol, guanfacine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from centrally acting alpha agonists may result in rebound hypertension.Minor (1)brimonidine increases effects of guanfacine by pharmacodynamic synergism. Minor/Significance Unknown.

• haloperidol

  Monitor Closely (1)haloperidol will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)brimonidine increases effects of haloperidol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• hydralazine

  Monitor Closely (1)hydralazine increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects.Minor (1)brimonidine increases effects of hydralazine by pharmacodynamic synergism. Minor/Significance Unknown.

• hydrochlorothiazide

  Monitor Closely (1)timolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of hydrochlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• hydromorphone

  Minor (1)brimonidine increases effects of hydromorphone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• hydroxyzine

  Minor (1)brimonidine increases effects of hydroxyzine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ibuprofen

  Monitor Closely (2)ibuprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ibuprofen both increase serum potassium. Use Caution/Monitor.

• ibuprofen IV

  Monitor Closely (2)ibuprofen IV decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ibuprofen IV both increase serum potassium. Use Caution/Monitor.

• iloperidone

  Minor (1)brimonidine increases effects of iloperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• iloprost

  Minor (1)brimonidine increases effects of iloprost by pharmacodynamic synergism. Minor/Significance Unknown.

• imaging agents (gadolinium)

  Minor (1)timolol, imaging agents (gadolinium). Mechanism: unknown. Minor/Significance Unknown. Increased risk of anaphylaxis from contrast media.

• imatinib

  Monitor Closely (1)imatinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• imidapril

  Minor (1)brimonidine increases effects of imidapril by pharmacodynamic synergism. Minor/Significance Unknown.

• imipramine

  Minor (1)imipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• indacaterol, inhaled

  Monitor Closely (1)indacaterol, inhaled, timolol. Other (see comment). Use Caution/Monitor. Comment: Beta-blockers and indacaterol may interfere with the effect of each other when administered concurrently. Beta-blockers may produce severe bronchospasm in COPD patients. Therefore, patients with COPD should not normally be treated with beta-blockers. However, under certain circumstances, e.g. as prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta-blockers in patients with COPD. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

• indapamide

  Monitor Closely (1)timolol increases and indapamide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of indapamide by pharmacodynamic synergism. Minor/Significance Unknown.

• indomethacin

  Monitor Closely (2)indomethacin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and indomethacin both increase serum potassium. Use Caution/Monitor.

• insulin aspart

  Monitor Closely (1)timolol, insulin aspart. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin degludec

  Monitor Closely (1)timolol, insulin degludec. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin degludec/insulin aspart

  Monitor Closely (1)timolol, insulin degludec/insulin aspart. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin detemir

  Monitor Closely (1)timolol, insulin detemir. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin glargine

  Monitor Closely (1)timolol, insulin glargine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin glulisine

  Monitor Closely (1)timolol, insulin glulisine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin inhaled

  Monitor Closely (1)timolol, insulin inhaled. Other (see comment). Modify Therapy/Monitor Closely. Comment: Beta-blockers may either increase or decrease the blood glucose lowering effect of insulin; beta-blockers can prolong hypoglycemia (interference with glycogenolysis) or cause hyperglycemia (insulin secretion inhibited).

• insulin lispro

  Monitor Closely (1)timolol, insulin lispro. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin NPH

  Monitor Closely (1)timolol, insulin NPH. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• insulin regular human

  Monitor Closely (1)timolol, insulin regular human. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers delay recovery of normoglycemia after insulin induced hypoglycemia; however, they also inhibit insulin secretion, so long term beta blocker Tx may result in reduced glucose tolerance. Insulin induced hypoglycemia may induce hypertension during non selective beta blocker Tx.

• iobenguane I 131

  Serious - Use Alternative (1)timolol will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.

• irbesartan

  Monitor Closely (3)timolol, irbesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  irbesartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of irbesartan by pharmacodynamic synergism. Use Caution/Monitor.

• isocarboxazid

  Contraindicated (1)isocarboxazid, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• isoproterenol

  Monitor Closely (2)timolol decreases effects of isoproterenol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and isoproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• isradipine

  Monitor Closely (1)timolol and isradipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of isradipine by pharmacodynamic synergism. Minor/Significance Unknown.

• ivabradine

  Monitor Closely (1)ivabradine, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Most patients receiving ivabradine will also be treated with a beta-blocker. The risk of bradycardia increases with coadministration of drugs that slow heart rate (eg, digoxin, amiodarone, beta-blockers). Monitor heart rate in patients taking ivabradine with other negative chronotropes.

• ketamine

  Monitor Closely (1)ketamine, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• ketanserin

  Minor (1)brimonidine increases effects of ketanserin by pharmacodynamic synergism. Minor/Significance Unknown.

• ketoprofen

  Monitor Closely (2)ketoprofen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ketoprofen both increase serum potassium. Use Caution/Monitor.

• ketorolac

  Monitor Closely (2)ketorolac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ketorolac both increase serum potassium. Use Caution/Monitor.

• ketorolac intranasal

  Monitor Closely (2)ketorolac intranasal decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and ketorolac intranasal both increase serum potassium. Use Caution/Monitor.

• labetalol

  Monitor Closely (1)labetalol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)labetalol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of labetalol by pharmacodynamic synergism. Minor/Significance Unknown.

• lasmiditan

  Monitor Closely (2)lasmiditan, brimonidine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.
  
  timolol increases effects of lasmiditan by pharmacodynamic synergism. Use Caution/Monitor. Lasmiditan has been associated with a lowering of heart rate (HR). In a drug interaction study, addition of a single 200-mg dose of lasmiditan to propranolol decreased HR by an additional 5 bpm compared to propranolol alone, for a mean maximum of 19 bpm.

• levalbuterol

  Monitor Closely (2)timolol decreases effects of levalbuterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and levalbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levobetaxolol

  Minor (1)levobetaxolol increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• levodopa

  Monitor Closely (1)levodopa increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.

• levorphanol

  Minor (1)brimonidine increases effects of levorphanol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lidocaine

  Monitor Closely (2)timolol, lidocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Increased effects of epinephrine in anesthetic; risk of hypertension and bradycardia. Do NOT D/C chronic beta blocker Tx prior to anesthetic administration. Consider selective beta 1 blocker (e.g., metoprolol).
  
  timolol increases levels of lidocaine by decreasing elimination. Use Caution/Monitor. Risk of hypertension and bradycardia. Consider selective beta 1 blocker (e.g., metoprolol).

• linezolid

  Contraindicated (1)linezolid, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• lisinopril

  Minor (1)brimonidine increases effects of lisinopril by pharmacodynamic synergism. Minor/Significance Unknown.

• lofepramine

  Minor (1)lofepramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• lofexidine

  Serious - Use Alternative (1)lofexidine, timolol. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.

• lopinavir

  Monitor Closely (1)lopinavir increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of PR prolongation and cardiac arrhythmias. .

• loprazolam

  Minor (1)brimonidine increases effects of loprazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lorazepam

  Minor (1)brimonidine increases effects of lorazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lorcaserin

  Monitor Closely (1)lorcaserin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lormetazepam

  Minor (1)brimonidine increases effects of lormetazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lornoxicam

  Monitor Closely (2)lornoxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and lornoxicam both increase serum potassium. Use Caution/Monitor.

• losartan

  Monitor Closely (3)losartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, losartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  brimonidine increases effects of losartan by pharmacodynamic synergism. Use Caution/Monitor.

• loxapine

  Minor (1)brimonidine increases effects of loxapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• loxapine inhaled

  Minor (1)brimonidine increases effects of loxapine inhaled by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• lumefantrine

  Serious - Use Alternative (1)lumefantrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• lurasidone

  Monitor Closely (2)lurasidone, brimonidine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased sedation.
  
  lurasidone increases effects of timolol by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.

• maitake

  Minor (1)maitake increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• maprotiline

  Minor (1)maprotiline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• maraviroc

  Monitor Closely (1)maraviroc will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• marijuana

  Monitor Closely (1)marijuana will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mavacamten

  Serious - Use Alternative (1)timolol, mavacamten. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Expect additive negative inotropic effects of mavacamten and other drugs that reduce cardiac contractility.

• mecamylamine

  Minor (1)brimonidine increases effects of mecamylamine by pharmacodynamic synergism. Minor/Significance Unknown.

• meclofenamate

  Monitor Closely (2)meclofenamate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and meclofenamate both increase serum potassium. Use Caution/Monitor.

• mefenamic acid

  Monitor Closely (2)mefenamic acid decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and mefenamic acid both increase serum potassium. Use Caution/Monitor.

• mefloquine

  Monitor Closely (1)mefloquine increases levels of timolol by decreasing metabolism. Use Caution/Monitor. Risk of arrhythmia.

• melatonin

  Minor (1)melatonin decreases toxicity of timolol by pharmacodynamic antagonism. Minor/Significance Unknown. Melatonin may correct beta blocker induced sleep disturbances.

• meloxicam

  Monitor Closely (2)meloxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and meloxicam both increase serum potassium. Use Caution/Monitor.

• meperidine

  Minor (1)brimonidine increases effects of meperidine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• mepivacaine

  Monitor Closely (1)timolol, mepivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• meprobamate

  Minor (1)brimonidine increases effects of meprobamate by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• metaproterenol

  Monitor Closely (2)timolol decreases effects of metaproterenol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and metaproterenol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methadone

  Minor (1)brimonidine increases effects of methadone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• methyclothiazide

  Monitor Closely (1)timolol increases and methyclothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. .Minor (1)brimonidine increases effects of methyclothiazide by pharmacodynamic synergism. Minor/Significance Unknown.

• methyldopa

  Monitor Closely (1)timolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension.

• methylphenidate

  Monitor Closely (1)methylphenidate will decrease the level or effect of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Methylphenidate may diminish antihypertensive effects. Monitor BP.

• metipranolol ophthalmic

  Minor (1)metipranolol ophthalmic increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• metolazone

  Monitor Closely (1)timolol increases and metolazone decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of metolazone by pharmacodynamic synergism. Minor/Significance Unknown.

• metoprolol

  Monitor Closely (1)metoprolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)metoprolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of metoprolol by pharmacodynamic synergism. Minor/Significance Unknown.

• metyrosine

  Minor (1)brimonidine increases effects of metyrosine by pharmacodynamic synergism. Minor/Significance Unknown.

• midazolam

  Minor (1)brimonidine increases effects of midazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• minoxidil

  Minor (1)brimonidine increases effects of minoxidil by pharmacodynamic synergism. Minor/Significance Unknown.

• mirabegron

  Monitor Closely (1)mirabegron will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• moexipril

  Minor (1)brimonidine increases effects of moexipril by pharmacodynamic synergism. Minor/Significance Unknown.

• morphine

  Minor (1)brimonidine increases effects of morphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• moxisylyte

  Monitor Closely (1)moxisylyte and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of moxisylyte by pharmacodynamic synergism. Minor/Significance Unknown.

• moxonidine

  Minor (1)brimonidine increases effects of moxonidine by pharmacodynamic synergism. Minor/Significance Unknown.

• nabumetone

  Monitor Closely (2)nabumetone decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and nabumetone both increase serum potassium. Use Caution/Monitor.

• nadolol

  Monitor Closely (1)nadolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)nadolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of nadolol by pharmacodynamic synergism. Minor/Significance Unknown.

• nalbuphine

  Minor (1)brimonidine increases effects of nalbuphine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• naproxen

  Monitor Closely (2)naproxen decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and naproxen both increase serum potassium. Use Caution/Monitor.

• nebivolol

  Monitor Closely (1)nebivolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)nebivolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of nebivolol by pharmacodynamic synergism. Minor/Significance Unknown.

• neostigmine

  Minor (1)timolol, neostigmine. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive bradycardia.

• nicardipine

  Monitor Closely (1)timolol and nicardipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of nicardipine by pharmacodynamic synergism. Minor/Significance Unknown.

• nifedipine

  Monitor Closely (1)timolol and nifedipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of nifedipine by pharmacodynamic synergism. Minor/Significance Unknown.

• nilotinib

  Monitor Closely (1)nilotinib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nisoldipine

  Monitor Closely (1)timolol and nisoldipine both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of nisoldipine by pharmacodynamic synergism. Minor/Significance Unknown.

• nitroglycerin rectal

  Monitor Closely (2)nitroglycerin rectal, brimonidine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .
  
  nitroglycerin rectal, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Beta-blockers blunt the reflex tachycardia produced by nitroglycerin without preventing its hypotensive effects. If beta-blockers are used with nitroglycerin in patients with angina pectoris, additional hypotensive effects may occur.

• noni juice

  Minor (1)timolol and noni juice both increase serum potassium. Minor/Significance Unknown.

• norepinephrine

  Monitor Closely (2)timolol decreases effects of norepinephrine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and norepinephrine decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nortriptyline

  Minor (1)nortriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• octacosanol

  Minor (1)octacosanol increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• olanzapine

  Minor (1)brimonidine increases effects of olanzapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• olmesartan

  Monitor Closely (3)timolol, olmesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  brimonidine increases effects of olmesartan by pharmacodynamic synergism. Use Caution/Monitor.
  
  olmesartan and timolol both increase serum potassium. Use Caution/Monitor.

• olodaterol inhaled

  Monitor Closely (1)timolol, olodaterol inhaled. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor. Beta-blockers and olodaterol may interfere with the effect of each other when administered concurrently. Beta-blockers may produce severe bronchospasm in COPD patients. Therefore, patients with COPD should not normally be treated with beta-blockers. However, under certain circumstances, e.g. as prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta-blockers in patients with COPD. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

• opium tincture

  Minor (1)brimonidine increases effects of opium tincture by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxaprozin

  Monitor Closely (2)oxaprozin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and oxaprozin both increase serum potassium. Use Caution/Monitor.

• oxazepam

  Minor (1)brimonidine increases effects of oxazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxycodone

  Minor (1)brimonidine increases effects of oxycodone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• oxymetazoline intranasal

  Monitor Closely (1)timolol increases effects of oxymetazoline intranasal by pharmacodynamic synergism. Use Caution/Monitor. When beta-2 receptors are antagonized by nonselective beta blockers, alpha1 vasoconstriction may be unopposed, thus increasing hypertensive effect. When oxymetazoline is combined with intranasal tetracaine for dental anesthesia, avoid or use an alternant anesthetic in patients taking nonselective beta blockers.

• oxymetazoline topical

  Monitor Closely (1)oxymetazoline topical increases and timolol decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• oxymorphone

  Minor (1)brimonidine increases effects of oxymorphone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• paliperidone

  Minor (1)brimonidine increases effects of paliperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• papaveretum

  Minor (1)brimonidine increases effects of papaveretum by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• parecoxib

  Monitor Closely (3)parecoxib will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  parecoxib decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and parecoxib both increase serum potassium. Use Caution/Monitor.

• paroxetine

  Serious - Use Alternative (1)paroxetine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• peginterferon alfa 2b

  Monitor Closely (1)peginterferon alfa 2b, timolol. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• penbutolol

  Monitor Closely (1)penbutolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)penbutolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of penbutolol by pharmacodynamic synergism. Minor/Significance Unknown.

• pentazocine

  Minor (1)brimonidine increases effects of pentazocine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• pentobarbital

  Monitor Closely (1)pentobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of pentobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of pentobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• perindopril

  Minor (1)brimonidine increases effects of perindopril by pharmacodynamic synergism. Minor/Significance Unknown.

• perphenazine

  Monitor Closely (1)perphenazine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)brimonidine increases effects of perphenazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• phenelzine

  Contraindicated (1)phenelzine, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• phenobarbital

  Monitor Closely (1)phenobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of phenobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of phenobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• phenoxybenzamine

  Monitor Closely (1)phenoxybenzamine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of phenoxybenzamine by pharmacodynamic synergism. Minor/Significance Unknown.

• phentolamine

  Monitor Closely (1)phentolamine and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of phentolamine by pharmacodynamic synergism. Minor/Significance Unknown.

• phenylephrine

  Monitor Closely (1)timolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

• phenylephrine PO

  Monitor Closely (1)timolol increases effects of phenylephrine PO by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

• physostigmine

  Minor (1)timolol, physostigmine. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive bradycardia.

• pilocarpine

  Minor (1)pilocarpine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• pimozide

  Minor (1)brimonidine increases effects of pimozide by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• pindolol

  Monitor Closely (1)pindolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)pindolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of pindolol by pharmacodynamic synergism. Minor/Significance Unknown.

• pirbuterol

  Monitor Closely (2)timolol decreases effects of pirbuterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and pirbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• piroxicam

  Monitor Closely (2)piroxicam decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and piroxicam both increase serum potassium. Use Caution/Monitor.

• ponesimod

  Monitor Closely (1)ponesimod and timolol both increase pharmacodynamic synergism. Use Caution/Monitor. Beta-blockers may have additive effects on lowering HR. Consider resting HR before initiating ponesimod in patients on stable dose of beta-blocker. Refer to the ponesimod prescribing information for more dosing information.

• potassium acid phosphate

  Monitor Closely (1)timolol and potassium acid phosphate both increase serum potassium. Modify Therapy/Monitor Closely.

• potassium chloride

  Monitor Closely (1)timolol and potassium chloride both increase serum potassium. Modify Therapy/Monitor Closely.

• potassium citrate

  Monitor Closely (1)timolol and potassium citrate both increase serum potassium. Modify Therapy/Monitor Closely.

• prazosin

  Monitor Closely (1)prazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of prazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• prilocaine

  Monitor Closely (1)timolol, prilocaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• primidone

  Monitor Closely (1)primidone decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of primidone. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of primidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• procarbazine

  Contraindicated (1)procarbazine, brimonidine. Mechanism: unknown. Contraindicated.

• prochlorperazine

  Minor (1)brimonidine increases effects of prochlorperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• promethazine

  Minor (1)brimonidine increases effects of promethazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• propafenone

  Monitor Closely (1)propafenone will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propofol

  Monitor Closely (1)propofol, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• propranolol

  Monitor Closely (1)propranolol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)propranolol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of propranolol by pharmacodynamic synergism. Minor/Significance Unknown.

• protriptyline

  Minor (1)protriptyline decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• quazepam

  Minor (1)brimonidine increases effects of quazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• quetiapine

  Minor (1)brimonidine increases effects of quetiapine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• quinacrine

  Monitor Closely (1)quinacrine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• quinapril

  Minor (1)brimonidine increases effects of quinapril by pharmacodynamic synergism. Minor/Significance Unknown.

• quinidine

  Serious - Use Alternative (1)quinidine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• ramipril

  Minor (1)brimonidine increases effects of ramipril by pharmacodynamic synergism. Minor/Significance Unknown.

• ranolazine

  Monitor Closely (1)ranolazine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• rasagiline

  Contraindicated (1)rasagiline, brimonidine. Mechanism: unknown. Contraindicated. Brimonidine should not be used in patients receiving MAO inhibitors.

• reishi

  Minor (1)reishi increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• risperidone

  Minor (1)brimonidine increases effects of risperidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• ritonavir

  Monitor Closely (1)ritonavir increases levels of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Potential for increased toxicity. Increased risk of hypotension, bradycardia, AV block, and prolonged PR interval. Consider lowering beta blocker dose.

• rivastigmine

  Serious - Use Alternative (1)timolol increases toxicity of rivastigmine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive bradycardia effect may result in syncope.

• rolapitant

  Monitor Closely (1)rolapitant will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• ropivacaine

  Monitor Closely (1)timolol, ropivacaine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Use extreme caution during concomitant use of bupivacaine and antihypertensive agents.

• sacubitril/valsartan

  Monitor Closely (3)brimonidine increases effects of sacubitril/valsartan by pharmacodynamic synergism. Use Caution/Monitor.
  
  sacubitril/valsartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  timolol, sacubitril/valsartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

• salicylates (non-asa)

  Monitor Closely (2)salicylates (non-asa) decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and salicylates (non-asa) both increase serum potassium. Use Caution/Monitor.

• salmeterol

  Monitor Closely (2)timolol decreases effects of salmeterol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and salmeterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• salsalate

  Monitor Closely (2)salsalate decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and salsalate both increase serum potassium. Use Caution/Monitor.

• saquinavir

  Monitor Closely (1)saquinavir, timolol. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR prolongation and cardiac arrhythmias.

• secobarbital

  Monitor Closely (1)secobarbital decreases levels of timolol by increasing metabolism. Use Caution/Monitor. Consider a higher beta-blocker dose during coadministration of secobarbital. Atenolol, sotalol, nadolol less likely to be affected than other beta blockers.Minor (1)brimonidine increases effects of secobarbital by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• selegiline

  Contraindicated (1)selegiline, brimonidine. Mechanism: unknown. Contraindicated. Coadministration is contraindicated.

• selegiline transdermal

  Contraindicated (1)selegiline transdermal, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• sertraline

  Monitor Closely (1)sertraline will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• sevoflurane

  Monitor Closely (1)sevoflurane, timolol. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• shepherd's purse

  Minor (1)shepherd's purse, timolol. Other (see comment). Minor/Significance Unknown. Comment: Theoretically, shepherd's purse may interfere with BP control.

• sildenafil

  Monitor Closely (1)timolol increases effects of sildenafil by additive vasodilation. Use Caution/Monitor. Sildenafil has systemic vasodilatory properties and may further lower blood pressure in patients taking antihypertensive medications. Monitor blood pressure response to sildenafil in patients receiving concurrent blood pressure lowering therapy.

• silodosin

  Monitor Closely (1)silodosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of silodosin by pharmacodynamic synergism. Minor/Significance Unknown.

• siponimod

  Monitor Closely (1)siponimod, timolol. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Caution when siponimod is initiated in patients receiving beta-blocker treatment because of additive effects on lowering heart rate. Temporary interruption of beta-blocker may be needed before initiating siponimod. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.

• sodium bicarbonate

  Monitor Closely (1)sodium bicarbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sodium citrate/citric acid

  Monitor Closely (1)sodium citrate/citric acid decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sotalol

  Monitor Closely (1)sotalol and timolol both increase serum potassium. Use Caution/Monitor.Serious - Use Alternative (1)sotalol and timolol both increase anti-hypertensive channel blocking. Avoid or Use Alternate Drug.Minor (1)brimonidine increases effects of sotalol by pharmacodynamic synergism. Minor/Significance Unknown.

• spironolactone

  Monitor Closely (1)timolol and spironolactone both increase serum potassium. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of spironolactone by pharmacodynamic synergism. Minor/Significance Unknown.

• stiripentol

  Monitor Closely (1)stiripentol, brimonidine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• succinylcholine

  Monitor Closely (1)timolol and succinylcholine both increase serum potassium. Use Caution/Monitor.

• sufentanil

  Minor (1)brimonidine increases effects of sufentanil by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• sulfasalazine

  Monitor Closely (2)sulfasalazine decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and sulfasalazine both increase serum potassium. Use Caution/Monitor.

• sulindac

  Monitor Closely (2)sulindac decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and sulindac both increase serum potassium. Use Caution/Monitor.

• tadalafil

  Monitor Closely (1)tadalafil increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

• tapentadol

  Minor (1)brimonidine increases effects of tapentadol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• telmisartan

  Monitor Closely (3)timolol, telmisartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  telmisartan and timolol both increase serum potassium. Use Caution/Monitor.
  
  brimonidine increases effects of telmisartan by pharmacodynamic synergism. Use Caution/Monitor.

• temazepam

  Minor (1)brimonidine increases effects of temazepam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• terazosin

  Monitor Closely (1)terazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of terazosin by pharmacodynamic synergism. Minor/Significance Unknown.

• terbinafine

  Monitor Closely (1)terbinafine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

• terbutaline

  Monitor Closely (2)timolol decreases effects of terbutaline by pharmacodynamic antagonism. Use Caution/Monitor.
  
  timolol increases and terbutaline decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• theophylline

  Monitor Closely (1)timolol, theophylline. Other (see comment). Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.

• thioridazine

  Monitor Closely (1)thioridazine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)brimonidine increases effects of thioridazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• thiothixene

  Minor (1)brimonidine increases effects of thiothixene by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• timolol

  Minor (1)brimonidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.

• tipranavir

  Monitor Closely (1)tipranavir will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tizanidine

  Minor (1)tizanidine increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.

• tolazamide

  Monitor Closely (1)timolol decreases effects of tolazamide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• tolbutamide

  Monitor Closely (1)timolol decreases effects of tolbutamide by pharmacodynamic antagonism. Use Caution/Monitor. Non selective beta blockers may also mask the symptoms of hypoglycemia.

• tolfenamic acid

  Monitor Closely (2)tolfenamic acid decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and tolfenamic acid both increase serum potassium. Use Caution/Monitor.

• tolmetin

  Monitor Closely (2)tolmetin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.
  
  timolol and tolmetin both increase serum potassium. Use Caution/Monitor.

• tolvaptan

  Monitor Closely (1)timolol and tolvaptan both increase serum potassium. Use Caution/Monitor.

• torsemide

  Monitor Closely (1)timolol increases and torsemide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)brimonidine increases effects of torsemide by pharmacodynamic synergism. Minor/Significance Unknown.

• tramadol

  Minor (1)brimonidine increases effects of tramadol by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• trandolapril

  Minor (1)brimonidine increases effects of trandolapril by pharmacodynamic synergism. Minor/Significance Unknown.

• tranylcypromine

  Contraindicated (1)tranylcypromine, brimonidine. Mechanism: unknown. Contraindicated. Contraindicated in mfr prescribing info.

• trazodone

  Minor (1)trazodone decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• treprostinil

  Minor (2)treprostinil increases effects of timolol by pharmacodynamic synergism. Minor/Significance Unknown.
  
  brimonidine increases effects of treprostinil by pharmacodynamic synergism. Minor/Significance Unknown.

• triamterene

  Monitor Closely (1)timolol and triamterene both increase serum potassium. Modify Therapy/Monitor Closely.Minor (1)brimonidine increases effects of triamterene by pharmacodynamic synergism. Minor/Significance Unknown.

• triazolam

  Minor (1)brimonidine increases effects of triazolam by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• triclofos

  Minor (1)brimonidine increases effects of triclofos by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• trifluoperazine

  Minor (1)brimonidine increases effects of trifluoperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• trimipramine

  Minor (1)trimipramine decreases effects of brimonidine by pharmacodynamic antagonism. Minor/Significance Unknown.

• triprolidine

  Minor (1)brimonidine increases effects of triprolidine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• umeclidinium bromide/vilanterol inhaled

  Serious - Use Alternative (1)timolol, umeclidinium bromide/vilanterol inhaled. pharmacodynamic antagonism. Avoid or Use Alternate Drug. If a beta-blocker must be used in patients with COPD taking a beta-agonist, consider using a beta-blocker that is beta-1 selective .

• valsartan

  Monitor Closely (3)timolol, valsartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.
  
  brimonidine increases effects of valsartan by pharmacodynamic synergism. Use Caution/Monitor.
  
  valsartan and timolol both increase serum potassium. Use Caution/Monitor.

• venlafaxine

  Monitor Closely (1)venlafaxine will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• verapamil

  Monitor Closely (1)timolol and verapamil both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)verapamil, timolol. Either increases toxicity of the other by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.Minor (1)brimonidine increases effects of verapamil by pharmacodynamic synergism. Minor/Significance Unknown.

• vilanterol/fluticasone furoate inhaled

  Serious - Use Alternative (1)timolol, vilanterol/fluticasone furoate inhaled. pharmacodynamic antagonism. Avoid or Use Alternate Drug. If a beta-blocker must be used in patients with COPD taking a beta-agonist, consider using a beta-blocker that is beta-1 selective .

• xipamide

  Monitor Closely (1)xipamide increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor.

• yohimbe

  Minor (1)timolol decreases toxicity of yohimbe by pharmacodynamic antagonism. Minor/Significance Unknown.

• ziprasidone

  Minor (1)brimonidine increases effects of ziprasidone by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• zotepine

  Minor (1)brimonidine increases effects of zotepine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.