timolol (Rx)

Brand and Other Names:Blocadren (DSC)
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Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

tablet

  • 5mg
  • 10mg
  • 20mg

Hypertension

10-30 mg PO q12hr

Maintenance: 20-40 mg/day

No more than 60 mg/day

Acute Myocardial Infarction

10 mg PO q12hr

Angina (Off-label)

15-45 mg/day PO divided q6-8hr

Migraine, Prophylaxis

Initial: 10 mg PO q12hr

Titrate to 10-30 mg/day

Additional Information

Less effective than thiazide diuretics in black and geriatric patients

Shown to decrease mortality in hypertension and post-myocardial infarction

Other Indications & Uses

Off-label: angina pectoris

<18 years old: safety & efficacy not established

Hypertension

10-30 mg PO q12hr

Maintenance: 20-40 mg/day

No more than 60 mg/day

Acute Myocardial Infarction

10 mg PO q12hr

Angina (Off-label)

15-45 mg/day PO divided q6-8hr

Migraine, ProphylaxisInitial

10 mg PO q12hr

Titrate to 10-30 mg/day

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Interactions

Interaction Checker

and timolol

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              Serious - Use Alternative (34)

              • 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.

              • 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 (228)

              • 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, 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.

              • 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.

              • diltiazem

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

              • 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.

              • 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

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

                timolol, irbesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

              • 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.

              • 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.

              • lurasidone

                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.

              • 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

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

                timolol, olmesartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

              • 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.

              • 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.

              • 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

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

                timolol, telmisartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

              • terazosin

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

              • terbinafine

                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

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

                timolol decreases effects of terbutaline by pharmacodynamic antagonism. Use Caution/Monitor.

              • theophylline

                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

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

              • tipranavir

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

              • tolazamide

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

              • tolbutamide

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

              • tolfenamic acid

                timolol and tolfenamic acid both increase serum potassium. Use Caution/Monitor.

                tolfenamic acid decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

              • tolmetin

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

                tolmetin decreases effects of timolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis.

              • tolvaptan

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

              • torsemide

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

              • triamterene

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

              • valsartan

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

                timolol, valsartan. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of fetal compromise if given during pregnancy.

              • venlafaxine

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

              • verapamil

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

              • xipamide

                xipamide increases effects of timolol by pharmacodynamic synergism. Use Caution/Monitor.

              Minor (28)

              • adenosine

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

              • agrimony

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

              • brimonidine

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

              • cevimeline

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

              • ciprofloxacin

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

              • cocaine

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

              • cornsilk

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

              • dihydroergotamine

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

              • dihydroergotamine intranasal

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

              • dipyridamole

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

              • escitalopram

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

              • fenoldopam

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

              • forskolin

                forskolin increases effects of timolol 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.

              • levobetaxolol

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

              • maitake

                maitake increases effects of timolol 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.

              • metipranolol ophthalmic

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

              • neostigmine

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

              • noni juice

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

              • octacosanol

                octacosanol increases effects of timolol 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.

              • reishi

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

              • shepherd's purse

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

              • tizanidine

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

              • treprostinil

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

              • yohimbe

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

              Previous
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              Adverse Effects

              1-10% (selected)

              Arrythmia

              Bradycardia

              Syncope

              Fatigue

              Headache

              Dyspnea

              <1% (selected)

              Bronchospasm

              Chest pain

              Edema

              Paresthesia

              Nausea

              Rales

              Frequency Not Defined

              Depression, decreased exercise tolerance, Raynaud's phenomenon

              May increase triglyceride levels and insulin resistance, and decrease HDL levels

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              Warnings

              Black Box Warnings

              May exacerbate ischemic heart disease following abrupt withdrawal

              Hypersensitivity to catecholamines has been observed during withdrawal

              Exacerbation of angina and, in some cases, myocardial infarction occurrence after abrupt discontinuation

              When discontinuing chronically administered beta-blockers (particularly with ischemic heart disease) gradually reduce dose over 1-2 wk and carefully monitor

              If angina markedly worsens or acute coronary insufficiency develops, reinstate beta-blocker administration promptly, at least temporarily (in addition to other measures appropriate for unstable angina)

              Warn patients against interruption or discontinuation of beta-blocker without physician advice

              Because coronary artery disease is common and may be unrecognized, slowly discontinue beta-blocker therapy, even in patients treated only for hypertension

              Contraindications

              Bronchial asthma/COPD

              Overt cardiac failure, sinus bradycardia, 2°/3° heart block, cardiogenic shock

              Hypersensitivity

              Sick sinus syndrome without permanent pacemaker

              Cautions

              IDDM, peripheral vascular disease, cerebrovascular insufficiency, liver disease, renal impairment, CHF, thyrotoxicosis

              Sudden discontinuation can exacerbate angina and lead to myocardial infarction

              Anesthesia/surgery (myocardial depression)

              Use in pheochromocytoma

              Increased risk of stroke after surgery

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              Pregnancy & Lactation

              Pregnancy Category: C

              Lactation: excreted in milk; Mfr's recommends avoid nursing (AAP Committee states compatible with nursing)

              Pregnancy Categories

              A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

              B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

              C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

              D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

              X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

              NA: Information not available.

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              Pharmacology

              Mechanism of Action

              Blocks response to beta-adrenergic stimulation to beta1 and beta2 receptors; may reduce blood pressure by decreasing sympathetic outflow; produces negative chronotropic and inotropic activity through unknown mechanism

              Pharmacokinetics

              Half-Life elimination: 2-2.7 hr

              Peak Plasma Time: 1-2 hr

              Duration: 4 hr

              Absorption: 90%

              Vd: 1.7 L/kg

              Bioavailability: 50%

              Protein Bound: 60%

              Dialyzable: No

              Metabolism: Liver, extensive first-pass

              Excretion: Urine (15-20%)

              Onset of Action

              • Hypotensive: 15-45 min
              • Peak effect: 0.5-2.5 hr
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              Images

              BRAND FORM. UNIT PRICE PILL IMAGE
              Betimol ophthalmic (eye)
              -
              0.5 % drops
              Betimol ophthalmic (eye)
              -
              0.5 % drops
              Betimol ophthalmic (eye)
              -
              0.25 % drops
              Betimol ophthalmic (eye)
              -
              0.5 % drops

              Copyright © 2010 First DataBank, Inc.

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              Patient Handout

              Patient Education
              timolol ophthalmic (eye)

              TIMOLOL SOLUTION - OPHTHALMIC

              (TIE-moh-lohl)

              COMMON BRAND NAME(S): Timoptic

              USES: This medication is used to treat high pressure inside the eye due to glaucoma (open angle-type) or other eye diseases (e.g., ocular hypertension). Lowering high pressure inside the eye helps to prevent blindness. This medication works by decreasing the amount of fluid within the eye. Timolol belongs to a class of drugs known as beta-blockers.

              HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start using timolol and each time you get a refill. If you have any questions, ask your doctor or pharmacist.To apply eye drops, wash your hands first. To avoid contamination, do not touch the dropper tip or let it touch your eye or any other surface.If you are wearing contact lenses, remove them before using eye drops. Wait at least 15 minutes before replacing your contact lenses.Tilt your head back, look upward, and pull down the lower eyelid to make a pouch. Hold the dropper directly over your eye and place one drop into the pouch as directed by your doctor, usually once in the morning or twice daily. Look downward, gently close your eyes, and place one finger at the corner of your eye (near the nose). Apply gentle pressure for 1 to 2 minutes before opening your eyes. This will prevent the medication from draining out. Try not to blink or rub your eye. If directed to use this medication in both eyes, repeat these steps for your other eye. Wait several minutes for your vision to clear before driving or operating machinery.Do not rinse the dropper. Replace the dropper cap after each use.If you are using another kind of eye medication (such as drops or ointments), wait at least 10 minutes before applying other medications. Use eye drops before eye ointments to allow the eye drops to enter the eye.Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same time(s) each day. Keep using this medication even if you feel well. Most people with glaucoma or high pressure in the eyes do not feel sick.

              SIDE EFFECTS: Temporary blurred vision, temporary burning/stinging/itching/redness of the eye, watery eyes, dry eyes, feeling as if something is in the eye, or headache may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: dizziness, eye pain/swelling/discharge, slow/irregular heartbeat, muscle weakness, mental/mood changes, coldness/numbness/pain in the hands or feet, vision changes, unusual tiredness/weakness.Get medical help right away if you have any very serious side effects, including: trouble breathing, sudden unexplained weight gain, chest pain, weakness on one side of the body, trouble speaking, confusion, persistent dizziness, fainting.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

              PRECAUTIONS: Before using timolol, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as preservatives like benzalkonium chloride), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: lung disease (e.g., current or past history of asthma, severe chronic obstructive pulmonary disease), certain types of irregular heartbeats (e.g., sinus bradycardia, second or third degree AV block), certain types of heart disease (e.g., severe heart failure, cardiogenic shock), kidney disease, liver disease, diabetes, low blood flow to the brain (cerebrovascular insufficiency), overactive thyroid disease, muscle weakness disorders, severe allergies.If you develop an eye infection or injury, or have eye surgery, check with your doctor about whether you should continue to use your current bottle of timolol. You may be advised to start using a new bottle.Before having surgery, tell your doctor or dentist that you are using this medication.If you have diabetes, this medication may prevent the fast/pounding heartbeat you would usually feel when your blood sugar level falls too low (hypoglycemia). Other symptoms of low blood sugar, such as dizziness and sweating, are unaffected by this drug.This drug may cause temporary blurred vision. Do not drive, use machinery, or do any activity that requires clear vision until you are sure you can perform such activities safely.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This drug passes into breast milk. Consult your doctor before breast-feeding.

              DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: oral beta-blockers (such as propranolol), clonidine, certain antidepressants (including SSRIs such as fluoxetine), digoxin, epinephrine, fingolimod, methyldopa, quinidine.

              OVERDOSE: This medicine may be harmful if swallowed. If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: trouble breathing or slow/irregular heartbeat.

              NOTES: Do not share this medication with others.Laboratory and/or medical tests (e.g., eye exams) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

              MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.

              STORAGE: Store at room temperature away from light and moisture. Avoid freezing. Keep all medications away from children and pets.This product is normally a colorless to light yellow solution. Discard the solution if it changes color, becomes cloudy, or develops particles.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

              Information last revised September 2021. Copyright(c) 2021 First Databank, Inc.

              IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

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              Formulary

              FormularyPatient Discounts

              Adding plans allows you to compare formulary status to other drugs in the same class.

              To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

              Adding plans allows you to:

              • View the formulary and any restrictions for each plan.
              • Manage and view all your plans together – even plans in different states.
              • Compare formulary status to other drugs in the same class.
              • Access your plan list on any device – mobile or desktop.

              The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

              Tier Description
              1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
              2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
              3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
              4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              NC NOT COVERED – Drugs that are not covered by the plan.
              Code Definition
              PA Prior Authorization
              Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
              QL Quantity Limits
              Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
              ST Step Therapy
              Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
              OR Other Restrictions
              Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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              Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.