metoprolol/hydrochlorothiazide (Rx)

Brand and Other Names:Lopressor HCT, Dutoprol
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Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

metoprolol/hydrochlorothiazide

tablet (Lopressor HCT)

  • 50mg/25mg
  • 100mg/25mg
  • 100mg/50mg

tablet (Dutoprol)

  • 25mg/12.5mg
  • 50mg/12.5mg
  • 100mg/12.5mg

Hypertension

Not indicated for initial therapy; if fixed combination represents dose titrated to patient’s needs, therapy with combination may be more convenient than with separate components

Lopressor HCT: metoprolol tartrate 50-100 mg and hydrochlorothiazide 25-50 mg PO daily in single or divided doses

Dutoprol: metoprolol succinate 25-100mg and hydrochlorothiazide 12.5 mg PO qDay as a single dose

When necessary, another antihypertensive agent may be added, beginning with 50% of usual recommended starting dose to avoid excessive fall in blood pressure

To minimize dose-independent side effects, begin combination therapy only after patient fails to achieve desired effect with monotherapy

Renal Impairment

Use caution in dosing/titrating patients with renal dysfunction

Cumulative effects of thiazides may develop with impaired renal function

Other Information

Combination may be substituted for titrated individual components

Withdraw gradually over a period of about 2 weeks

Geriatric: Start at low end of dosing range and titrate slowly

<18 years: Safety/efficacy not established

Hypertension

Not indicated for initial therapy; if fixed combination represents dose titrated to patient’s needs, therapy with combination may be more convenient than with separate components

Lopressor HCT: metoprolol tartrate 50-100 mg and hydrochlorothiazide 25-50 mg PO daily in single or divided doses

Dutoprol: metoprolol succinate 25-100mg amd hydrochlorothiazide 12.5 mg PO qDay as a single dose

When necessary, another antihypertensive agent may be added, beginning with 50% of usual recommended starting dose to avoid excessive fall in blood pressure

To minimize dose-independent side effects, begin combination therapy only after patient fails to achieve desired effect with monotherapy

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Interactions

Interaction Checker

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              • acebutolol

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

              • aminolevulinic acid oral

                aminolevulinic acid oral, hydrochlorothiazide. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid administering other phototoxic drugs with aminolevulinic acid oral for 24 hr during perioperative period.

              • aminolevulinic acid topical

                hydrochlorothiazide increases toxicity of aminolevulinic acid topical by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of photosensitizing drugs may enhance the phototoxic reaction to photodynamic therapy with aminolevulinic acid.

              • artemether/lumefantrine

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

              • atenolol

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

              • betaxolol

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

              • bisoprolol

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

              • carbamazepine

                carbamazepine, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of systemic hyponatremia.

              • carvedilol

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

              • celiprolol

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

              • chlorpromazine

                metoprolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

              • clonidine

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

              • cyclophosphamide

                hydrochlorothiazide increases toxicity of cyclophosphamide by decreasing renal clearance. Avoid or Use Alternate Drug. Increased myelosuppressive effects.

              • cyclosporine

                cyclosporine, hydrochlorothiazide. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of systemic hyponatremia.

              • dacomitinib

                dacomitinib will increase the level or effect of metoprolol 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 increases toxicity of metoprolol by unspecified interaction mechanism. Avoid or Use Alternate Drug. Can increase risk of bradycardia.

              • diltiazem

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

              • dofetilide

                hydrochlorothiazide increases levels of dofetilide by decreasing renal clearance. Contraindicated. Risk of prolonged QTc interval.

              • elvitegravir/cobicistat/emtricitabine/tenofovir DF

                elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

              • esmolol

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

              • fexinidazole

                fexinidazole, metoprolol. 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 metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

              • givosiran

                givosiran will increase the level or effect of metoprolol 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.

              • isocarboxazid

                isocarboxazid, hydrochlorothiazide. Other (see comment). Contraindicated. Comment: Additive hypotensive effects may be seen when MAOI's are combined with antihypertensives.

              • labetalol

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

              • lofexidine

                lofexidine, hydrochlorothiazide. 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.

                lofexidine, metoprolol. 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 metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

              • methyl aminolevulinate

                hydrochlorothiazide, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.

              • nadolol

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

              • nebivolol

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

              • paroxetine

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

              • penbutolol

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

              • pindolol

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

              • propranolol

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

              • quinidine

                quinidine will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. If concurrent therapy required, monitor cardiac function carefully (blood pressure, heart rate). A dosage adjustment may be required for both drugs.

              • rivastigmine

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

              • sotalol

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

              • squill

                hydrochlorothiazide increases toxicity of squill by Other (see comment). Avoid or Use Alternate Drug. Comment: Potassium depletion may enhance toxicity of squill.

              • thioridazine

                metoprolol, thioridazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

              • thiothixene

                metoprolol, thiothixene. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

              • timolol

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

              • tretinoin

                hydrochlorothiazide, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

              • tretinoin topical

                hydrochlorothiazide, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

              • verapamil

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

              Monitor Closely (278)

              • abiraterone

                abiraterone increases levels of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

              • acebutolol

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

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

              • aceclofenac

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

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

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

              • acemetacin

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

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

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

              • albiglutide

                hydrochlorothiazide decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Monitor glycemic control especially when initiating, discontinuing, or increasing thiazide diuretic dose.

              • albuterol

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

                metoprolol decreases effects of albuterol by pharmacodynamic antagonism. Use Caution/Monitor.

              • albuterol

                albuterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • aldesleukin

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

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

              • alfuzosin

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

              • amifostine

                amifostine, hydrochlorothiazide. 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.

              • aluminum hydroxide

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

              • amifostine

                amifostine, metoprolol. 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

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

                amiloride increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

              • amiodarone

                amiodarone will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Monitor cardiac function carefully and observe for signs of bradycardia or heart block when amiodarone and a beta adrenergic blocker are coadministered. Amiodarone should be used with caution in patients receiving a beta adrenergic blocker, particularly if there is suspicion of underlying dysfunction of the sinus node, such as bradycardia or sick sinus syndrome, or if there is partial AV block.

                amiodarone, metoprolol. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of cardiotoxicity with bradycardia.

                amiodarone will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • amobarbital

                amobarbital decreases levels of metoprolol 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.

              • amoxicillin

                amoxicillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • arformoterol

                metoprolol decreases effects of arformoterol by pharmacodynamic antagonism. Use Caution/Monitor.

                arformoterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

              • asenapine

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

                asenapine and metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

              • aspirin

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

              • aspirin

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

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

              • aspirin rectal

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

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

                metoprolol and aspirin rectal both increase serum potassium. Use Caution/Monitor.

              • aspirin/citric acid/sodium bicarbonate

                metoprolol and aspirin/citric acid/sodium bicarbonate both increase serum potassium. Use Caution/Monitor.

                aspirin/citric acid/sodium bicarbonate increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

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

              • atazanavir

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

              • atenolol

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

              • atenolol

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

              • avanafil

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

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

              • beclomethasone, inhaled

                beclomethasone, inhaled increases toxicity of hydrochlorothiazide by increasing elimination. Use Caution/Monitor. May increase the hypokalemic effects of thiazide diuretics.

              • bendroflumethiazide

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

              • benazepril

                benazepril increases toxicity of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Enhanced hypotensive effects; increased risk of nephrotoxicity.

              • bendroflumethiazide

                bendroflumethiazide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • betaxolol

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

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

              • bismuth subsalicylate

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

              • bisoprolol

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

              • bisoprolol

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

              • bretylium

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

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

              • bumetanide

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

                bumetanide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • buprenorphine, long-acting injection

                buprenorphine, long-acting injection decreases effects of hydrochlorothiazide by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Opioids can reduce diuretic efficacy by inducing antidiuretic hormone release.

              • bupropion

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

              • butabarbital

                butabarbital decreases levels of metoprolol 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 metoprolol 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.

              • calcifediol

                hydrochlorothiazide increases toxicity of calcifediol by Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics may increase serum calcium by decreasing urinary calcium excretion.

              • calcium acetate

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

              • calcium carbonate

                calcium carbonate decreases effects of metoprolol by unspecified interaction mechanism. Use Caution/Monitor.

                calcium carbonate decreases levels of metoprolol 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 metoprolol by unspecified interaction mechanism. Use Caution/Monitor.

              • calcium citrate

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

              • calcium gluconate

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

              • candesartan

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

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

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

              • captopril

                captopril, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Increased risk of nephrotoxicity. Monitor blood pressure and renal function.

              • carbenoxolone

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

              • carbenoxolone

                hydrochlorothiazide and carbenoxolone both decrease serum potassium. Use Caution/Monitor.

              • carbidopa

                carbidopa increases effects of hydrochlorothiazide 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.

                carbidopa increases effects of metoprolol 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 metoprolol both increase serum potassium. Use Caution/Monitor.

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

              • cefprozil

                hydrochlorothiazide will increase the level or effect of cefprozil by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • celecoxib

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

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

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

              • celecoxib

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

              • celiprolol

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

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

                hydrochlorothiazide decreases levels of celiprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              • chloroquine

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

              • chlorothiazide

                chlorothiazide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • chlorothiazide

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

              • chlorthalidone

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

                chlorthalidone and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • cholestyramine

                cholestyramine decreases levels of hydrochlorothiazide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              • choline magnesium trisalicylate

                metoprolol and choline magnesium trisalicylate both increase serum potassium. Use Caution/Monitor.

                choline magnesium trisalicylate decreases effects of metoprolol 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 metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

              • citalopram

                citalopram increases levels of metoprolol by decreasing metabolism. Use Caution/Monitor. Increased metoprolol plasma levels have been associated with decreased cardioselectivity.

                hydrochlorothiazide, citalopram. pharmacodynamic synergism. Use Caution/Monitor. Possible additive hyponatremia.

              • clevidipine

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

              • cornsilk

                cornsilk increases effects of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of hypokalemia (theoretical interaction).

              • clonidine

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

                clonidine, metoprolol. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive sympatholytic action may worsen sinus node dysfunction and atrioventricular (AV) block.

              • cobicistat

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

              • corticotropin

                corticotropin increases toxicity of hydrochlorothiazide by increasing renal clearance. Use Caution/Monitor. May enhance hypokalemic effect of thiazide diuretics.

              • cyclopenthiazide

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

                cyclopenthiazide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • cyclosporine

                cyclosporine increases toxicity of hydrochlorothiazide by unspecified interaction mechanism. Use Caution/Monitor. Coadministration of hydrochlorothiazide with cyclosporine may increase the risk of hypermagnesemia, hyperuricemia, and possible nephrotoxicity.

              • darifenacin

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

              • darunavir

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

              • dasiglucagon

                metoprolol 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.

              • deflazacort

                hydrochlorothiazide and deflazacort both decrease serum potassium. Use Caution/Monitor.

              • desflurane

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

              • desvenlafaxine

                desvenlafaxine will increase the level or effect of metoprolol 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

              • diazoxide

                hydrochlorothiazide increases toxicity of diazoxide by unspecified interaction mechanism. Use Caution/Monitor. May enhance hyperglycemic effects of diazoxide.

              • dichlorphenamide

                dichlorphenamide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • diclofenac

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

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

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

              • dicloxacillin

                dicloxacillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • diflunisal

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

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

              • diflunisal

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

              • digoxin

                hydrochlorothiazide increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor. Hypokalemia increases digoxin effects.

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

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

                digoxin will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

                metoprolol increases effects of digoxin by pharmacodynamic synergism. Use Caution/Monitor. Enhanced bradycardia.

              • diltiazem

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

              • dobutamine

                dobutamine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • diphenhydramine

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

              • dobutamine

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

                metoprolol decreases effects of dobutamine by pharmacodynamic antagonism. Use Caution/Monitor.

              • dofetilide

                dofetilide will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • dopexamine

                dopexamine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

                metoprolol decreases effects of dopexamine by pharmacodynamic antagonism. Use Caution/Monitor.

              • doxazosin

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

              • drospirenone

                drospirenone increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

              • dronedarone

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

              • drospirenone

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

              • duloxetine

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

              • eliglustat

                eliglustat increases levels of metoprolol 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.

              • empagliflozin

                empagliflozin, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of empagliflozin with diuretics results in increased urine volume and frequency of voids, which might enhance the potential for volume depletion.

              • ephedrine

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

                ephedrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

                metoprolol decreases effects of ephedrine by pharmacodynamic antagonism. Use Caution/Monitor.

              • epinephrine

                epinephrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

                metoprolol decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor.

              • epinephrine racemic

                metoprolol decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor.

                metoprolol increases and epinephrine racemic decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

                epinephrine racemic and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • eprosartan

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

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

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

              • esmolol

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

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

              • ethacrynic acid

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

                ethacrynic acid and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • ether

                metoprolol, 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

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

              • etodolac

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

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

              • etomidate

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

              • exenatide injectable solution

                hydrochlorothiazide decreases effects of exenatide injectable solution by pharmacodynamic antagonism. Use Caution/Monitor. Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Monitor glycemic control especially when initiating, discontinuing, or increasing thiazide diuretic dose.

              • exenatide injectable suspension

                hydrochlorothiazide decreases effects of exenatide injectable suspension by pharmacodynamic antagonism. Use Caution/Monitor. Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Monitor glycemic control especially when initiating, discontinuing, or increasing thiazide diuretic dose.

              • fedratinib

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

              • felodipine

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

              • fenbufen

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

              • fenoprofen

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

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

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

              • fentanyl

                fentanyl decreases effects of hydrochlorothiazide by Other (see comment). Modify Therapy/Monitor Closely. Comment: Fentanyl can reduce the efficacy of diuretics by inducing antidiuretic hormone release. Fentanyl may also lead to acute urinary retention by causing bladder sphincter spasm (particularly in men with enlarged prostates).

              • fingolimod

                metoprolol 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.

              • fentanyl intranasal

                fentanyl intranasal decreases effects of hydrochlorothiazide by Other (see comment). Modify Therapy/Monitor Closely. Comment: Fentanyl can reduce the efficacy of diuretics by inducing antidiuretic hormone release. Fentanyl may also lead to acute urinary retention by causing bladder sphincter spasm (particularly in men with enlarged prostates).

              • fentanyl transdermal

                fentanyl transdermal decreases effects of hydrochlorothiazide by Other (see comment). Modify Therapy/Monitor Closely. Comment: Fentanyl can reduce the efficacy of diuretics by inducing antidiuretic hormone release. Fentanyl may also lead to acute urinary retention by causing bladder sphincter spasm (particularly in men with enlarged prostates).

              • fentanyl transmucosal

                fentanyl transmucosal decreases effects of hydrochlorothiazide by Other (see comment). Modify Therapy/Monitor Closely. Comment: Fentanyl can reduce the efficacy of diuretics by inducing antidiuretic hormone release. Fentanyl may also lead to acute urinary retention by causing bladder sphincter spasm (particularly in men with enlarged prostates).

              • flurbiprofen

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

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

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

              • formoterol

                formoterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

                metoprolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.

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

              • furosemide

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

                furosemide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • gentamicin

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

                hydrochlorothiazide and gentamicin both decrease serum potassium. Use Caution/Monitor.

              • glucagon

                glucagon decreases toxicity of metoprolol 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.

              • ibuprofen

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

              • glucagon intranasal

                glucagon intranasal decreases toxicity of metoprolol 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.

              • haloperidol

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

              • hydralazine

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

              • hydrochlorothiazide

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

                hydrochlorothiazide, metoprolol. Either increases toxicity of the other by Other (see comment). Modify Therapy/Monitor Closely. Comment: May cause idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma, which can lead to permanent vision loss.

              • ibuprofen

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

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

              • ibuprofen IV

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

                metoprolol and ibuprofen IV both increase serum potassium. Use Caution/Monitor.

                hydrochlorothiazide will increase the level or effect of ibuprofen IV by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

                ibuprofen IV increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. NSAIDs may decrease the therapeutic effects of thiazide-like diuretics; may also enhance nephrotoxic effects.

              • imatinib

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

              • indacaterol, inhaled

                hydrochlorothiazide, indacaterol, inhaled. serum potassium. Use Caution/Monitor. Combination may increase risk of hypokalemia.

                indacaterol, inhaled, hydrochlorothiazide. Other (see comment). Use Caution/Monitor. Comment: Caution is advised in the coadministration of indacaterol neohaler with non-potassium-sparing diuretics.

              • indacaterol, inhaled

                indacaterol, inhaled, metoprolol. 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

                hydrochlorothiazide and indapamide both decrease serum potassium. Use Caution/Monitor.

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

              • indomethacin

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

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

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

              • insulin degludec

                metoprolol, 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).

                hydrochlorothiazide decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, possibly by diuretic-induced hpokalemia.

              • insulin degludec/insulin aspart

                metoprolol, 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).

                hydrochlorothiazide decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, possibly by diuretic-induced hpokalemia.

              • insulin inhaled

                metoprolol, 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).

                hydrochlorothiazide decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Diuretics may cause hyperglycemia and glycosuria in patients with diabetes mellitus, possibly by diuretic-induced hpokalemia.

              • irbesartan

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

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

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

              • isoproterenol

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

                isoproterenol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

                metoprolol decreases effects of isoproterenol by pharmacodynamic antagonism. Use Caution/Monitor.

              • isradipine

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

              • juniper

                juniper, hydrochlorothiazide. Other (see comment). Use Caution/Monitor. Comment: Juniper may potentiate or interfere with diuretic therapy. Juniper has diuretic effects, but may cause kidney damage at large doses.

              • ivabradine

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

              • ketoprofen

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

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

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

              • ketorolac

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

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

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

              • ketorolac intranasal

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

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

                metoprolol and ketorolac intranasal both increase serum potassium. Use Caution/Monitor.

              • labetalol

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

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

              • levalbuterol

                metoprolol decreases effects of levalbuterol by pharmacodynamic antagonism. Use Caution/Monitor.

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

                levalbuterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • levodopa

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

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

              • lily of the valley

                hydrochlorothiazide increases toxicity of lily of the valley by Other (see comment). Use Caution/Monitor. Comment: Increased risk of cardiac toxicity due to K+ depletion.

              • lorcaserin

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

              • liraglutide

                hydrochlorothiazide decreases effects of liraglutide by pharmacodynamic antagonism. Use Caution/Monitor. Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Monitor glycemic control especially when initiating, discontinuing, or increasing thiazide diuretic dose.

              • lithium

                hydrochlorothiazide increases toxicity of lithium by decreasing elimination. Use Caution/Monitor.

              • lornoxicam

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

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

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

              • losartan

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

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

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

              • lurasidone

                lurasidone increases effects of metoprolol 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.

                lurasidone increases effects of hydrochlorothiazide 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

                maitake increases effects of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of hypokalemia (theoretical interaction).

              • maraviroc

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

              • marijuana

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

              • meclofenamate

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

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

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

              • mefenamic acid

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

                metoprolol and mefenamic acid both increase serum potassium. Use Caution/Monitor.

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

              • mefloquine

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

              • meloxicam

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

              • meloxicam

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

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

              • metaproterenol

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

                metaproterenol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

                metoprolol decreases effects of metaproterenol by pharmacodynamic antagonism. Use Caution/Monitor.

              • methoxsalen

                methoxsalen, hydrochlorothiazide. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

              • methyclothiazide

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

              • metolazone

                hydrochlorothiazide and metolazone both decrease serum potassium. Use Caution/Monitor.

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

              • metoprolol

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

                hydrochlorothiazide, metoprolol. Either increases toxicity of the other by Other (see comment). Modify Therapy/Monitor Closely. Comment: May cause idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma, which can lead to permanent vision loss.

              • mirabegron

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

              • mometasone inhaled

                mometasone inhaled increases toxicity of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Corticosteroids may increase hypokalemic effect of loop diuretics.

              • moxisylyte

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

              • mycophenolate

                hydrochlorothiazide will increase the level or effect of mycophenolate by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • nabumetone

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

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

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

              • nadolol

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

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

              • nafcillin

                nafcillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • naproxen

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

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

              • naproxen

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

              • nebivolol

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

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

              • nicardipine

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

              • nitroglycerin rectal

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

              • nifedipine

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

              • nilotinib

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

              • nisoldipine

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

              • nitroglycerin rectal

                nitroglycerin rectal, metoprolol. 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

                metoprolol decreases effects of norepinephrine by pharmacodynamic antagonism. Use Caution/Monitor.

                norepinephrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

              • oliceridine

                oliceridine decreases effects of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor for signs of diminished diuresis and/or effects on blood pressure and increase dosage of the diuretic as needed. .

              • olmesartan

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

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

              • olmesartan

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

              • olodaterol inhaled

                hydrochlorothiazide and olodaterol inhaled both decrease serum potassium. Use Caution/Monitor.

              • oxaprozin

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

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

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

              • oxymetazoline topical

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

              • parecoxib

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

              • panobinostat

                panobinostat will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Panobinostat can increase the levels and effects of sensitive CYP2D6 substrates or those with a narrow therapeutic index CYP2D6.

              • parecoxib

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

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

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

              • peginterferon alfa 2b

                peginterferon alfa 2b, metoprolol. 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 increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

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

              • penicillin G aqueous

                penicillin G aqueous, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • pentobarbital

                pentobarbital decreases levels of metoprolol 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 metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

              • phenobarbital

                phenobarbital decreases levels of metoprolol 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 metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

              • phentolamine

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

              • pindolol

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

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

              • pirbuterol

                metoprolol decreases effects of pirbuterol by pharmacodynamic antagonism. Use Caution/Monitor.

                pirbuterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

              • piroxicam

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

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

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

              • pivmecillinam

                pivmecillinam, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • ponesimod

                ponesimod and metoprolol 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.

              • porfimer

                hydrochlorothiazide, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.

              • potassium acid phosphate

                potassium acid phosphate increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

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

              • potassium chloride

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

                potassium chloride increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

              • potassium citrate

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

                potassium citrate increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

              • prazosin

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

              • probenecid

                hydrochlorothiazide will increase the level or effect of probenecid by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • primidone

                primidone decreases levels of metoprolol 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.

              • procainamide

                hydrochlorothiazide will increase the level or effect of procainamide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • propafenone

                propafenone will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. If concurrent therapy is required, monitor cardiac function carefully, particularly blood pressure. A dosage adjustment for the beta blocker may be required.

              • propofol

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

              • propranolol

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

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

              • quinacrine

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

              • quinidine

                quinidine will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.

              • ranolazine

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

              • rifabutin

                rifabutin decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor. Enzyme induction effect may continue for up to 3-4 weeks.

              • rifampin

                rifampin decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor.

              • rifapentine

                rifapentine decreases levels of metoprolol by increasing metabolism. Use Caution/Monitor.

              • ritonavir

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

              • rolapitant

                rolapitant will increase the level or effect of metoprolol 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.

              • sacubitril/valsartan

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

                sacubitril/valsartan and metoprolol both increase serum potassium. Use Caution/Monitor.

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

              • salicylates (non-asa)

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

                metoprolol and salicylates (non-asa) both increase serum potassium. Use Caution/Monitor.

                salicylates (non-asa) increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.

              • salmeterol

                metoprolol decreases effects of salmeterol by pharmacodynamic antagonism. Use Caution/Monitor.

                salmeterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

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

              • salsalate

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

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

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

              • saquinavir

                saquinavir, metoprolol. 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.

              • shark cartilage

                hydrochlorothiazide, shark cartilage. Other (see comment). Use Caution/Monitor. Comment: May lead to hypercalcemia (theoretical).

              • secobarbital

                secobarbital decreases levels of metoprolol 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 metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

              • sevoflurane

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

              • sildenafil

                metoprolol 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 metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.

              • siponimod

                siponimod, metoprolol. 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 metoprolol 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 metoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

              • sodium sulfate/?magnesium sulfate/potassium chloride

                sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.

              • sodium sulfate/potassium sulfate/magnesium sulfate

                sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.

              • sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol

                hydrochlorothiazide and sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol both decrease serum potassium. Modify Therapy/Monitor Closely.

              • sotalol

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

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

              • spironolactone

                spironolactone increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

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

              • succinylcholine

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

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

              • sulfasalazine

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

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

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

              • sulindac

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

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

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

              • tadalafil

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

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

              • telmisartan

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

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

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

              • temocillin

                temocillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • terazosin

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

              • terbinafine

                terbinafine will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

              • terbutaline

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

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

                metoprolol increases effects of terbutaline by pharmacodynamic synergism. Use Caution/Monitor.

                terbutaline and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • theophylline

                metoprolol, 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.

              • ticarcillin

                ticarcillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              • thioridazine

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

              • timolol

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

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

              • tipranavir

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

              • tolfenamic acid

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

              • tolfenamic acid

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

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

              • tolmetin

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

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

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

              • tolvaptan

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

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

              • toremifene

                hydrochlorothiazide, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

              • torsemide

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

              • torsemide

                torsemide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.

              • triamterene

                triamterene increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

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

              • trientine

                hydrochlorothiazide decreases levels of trientine by increasing renal clearance. Use Caution/Monitor.

              • valsartan

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

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

              • umeclidinium bromide/vilanterol inhaled

                umeclidinium bromide/vilanterol inhaled and hydrochlorothiazide both decrease serum potassium. Modify Therapy/Monitor Closely. Electrocardiographic changes and/or hypokalemia associated with non?potassium-sparing diuretics may worsen with concomitant beta-agonists, particularly if recommended dose is exceeded

              • valsartan

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

              • venlafaxine

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

              • verapamil

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

              • vilanterol/fluticasone furoate inhaled

                vilanterol/fluticasone furoate inhaled and hydrochlorothiazide both decrease serum potassium. Modify Therapy/Monitor Closely. Beta-agonists may acutely worsen ECG changes and/or hypokalemia resulting from non-potassium-sparing diuretics

              • vitamin D

                hydrochlorothiazide increases effects of vitamin D by Other (see comment). Use Caution/Monitor. Comment: Combination may increase hypercalcemic effect of vitamin D analogs. Use with caution.

              • xipamide

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

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

              Minor (175)

              • acarbose

                hydrochlorothiazide decreases effects of acarbose by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • aceclofenac

                hydrochlorothiazide will increase the level or effect of aceclofenac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • acemetacin

                hydrochlorothiazide will increase the level or effect of acemetacin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • acyclovir

                hydrochlorothiazide will increase the level or effect of acyclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • adenosine

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

              • agrimony

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

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

              • albuterol

                albuterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • antipyrine

                metoprolol increases levels of antipyrine by decreasing metabolism. Minor/Significance Unknown.

              • aminohippurate sodium

                hydrochlorothiazide will increase the level or effect of aminohippurate sodium by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • ampicillin

                hydrochlorothiazide increases levels of ampicillin by decreasing renal clearance. Minor/Significance Unknown.

              • arformoterol

                arformoterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • aspirin

                hydrochlorothiazide will increase the level or effect of aspirin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • aspirin rectal

                hydrochlorothiazide will increase the level or effect of aspirin rectal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • aspirin/citric acid/sodium bicarbonate

                hydrochlorothiazide will increase the level or effect of aspirin/citric acid/sodium bicarbonate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • balsalazide

                hydrochlorothiazide will increase the level or effect of balsalazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • bendroflumethiazide

                bendroflumethiazide will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • birch

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

              • bitter melon

                bitter melon, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • brimonidine

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

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

              • budesonide

                budesonide, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • cevimeline

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

              • calcitriol topical

                calcitriol topical, hydrochlorothiazide. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Potential additive hypercalcemia.

              • calcium acetate

                hydrochlorothiazide increases levels of calcium acetate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              • calcium carbonate

                hydrochlorothiazide increases levels of calcium carbonate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              • calcium chloride

                hydrochlorothiazide increases levels of calcium chloride by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              • calcium citrate

                hydrochlorothiazide increases levels of calcium citrate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              • calcium gluconate

                hydrochlorothiazide increases levels of calcium gluconate by decreasing renal clearance. Minor/Significance Unknown. Risk of alkalosis, hypercalcemia.

              • carbenoxolone

                hydrochlorothiazide, carbenoxolone. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive hypokalemic effects.

              • cefadroxil

                cefadroxil will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • cefamandole

                cefamandole will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • cefpirome

                cefpirome will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • cefprozil

                cefprozil will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • ceftibuten

                ceftibuten will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • celecoxib

                hydrochlorothiazide will increase the level or effect of celecoxib by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • cephalexin

                cephalexin will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • chlorothiazide

                chlorothiazide will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • chlorpropamide

                hydrochlorothiazide will increase the level or effect of chlorpropamide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

                hydrochlorothiazide decreases effects of chlorpropamide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • chlorthalidone

                chlorthalidone will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • ciprofloxacin

                ciprofloxacin increases levels of metoprolol by decreasing metabolism. Minor/Significance Unknown. Ciprofloxacin may increase metoprolol plasma concentrations however mechanism is unknown. Further clinical evidence is needed but it may be appropriate to monitor patients during concomitant therapy with ciprofloxacin.

              • cocaine

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

              • colestipol

                colestipol decreases levels of hydrochlorothiazide by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

              • cornsilk

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

              • cortisone

                cortisone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • cosyntropin

                cosyntropin, hydrochlorothiazide. pharmacodynamic synergism. Minor/Significance Unknown. Possible enhanced electrolyte loss.

              • cyclopenthiazide

                cyclopenthiazide will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • deflazacort

                deflazacort, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • dexamethasone

                dexamethasone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • diazepam

                metoprolol increases effects of diazepam by decreasing metabolism. Minor/Significance Unknown.

              • diazoxide

                diazoxide, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hyperglycemia.

              • diclofenac

                hydrochlorothiazide will increase the level or effect of diclofenac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • diflunisal

                hydrochlorothiazide will increase the level or effect of diflunisal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • dihydroergotamine

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

              • dihydroergotamine intranasal

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

              • dipyridamole

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

              • dobutamine

                dobutamine, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • dopexamine

                dopexamine, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • ephedrine

                ephedrine, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • epinephrine

                epinephrine, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • epinephrine racemic

                epinephrine racemic, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • epoprostenol

                epoprostenol increases effects of hydrochlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.

              • escitalopram

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

              • etodolac

                hydrochlorothiazide will increase the level or effect of etodolac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • fenbufen

                hydrochlorothiazide will increase the level or effect of fenbufen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • fenoldopam

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

              • fenoprofen

                hydrochlorothiazide will increase the level or effect of fenoprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • fludrocortisone

                fludrocortisone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • flurbiprofen

                hydrochlorothiazide will increase the level or effect of flurbiprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • fo-ti

                fo-ti increases effects of hydrochlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia (theoretical).

              • folic acid

                hydrochlorothiazide decreases levels of folic acid by increasing renal clearance. Minor/Significance Unknown.

              • formoterol

                formoterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • forskolin

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

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

              • ganciclovir

                hydrochlorothiazide will increase the level or effect of ganciclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • guanfacine

                metoprolol, guanfacine. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Selective beta blocker administration during withdrawal from centrally acting alpha agonists may result in rebound hypertension.

              • glimepiride

                hydrochlorothiazide decreases effects of glimepiride by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • glipizide

                hydrochlorothiazide decreases effects of glipizide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • glyburide

                hydrochlorothiazide decreases effects of glyburide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • goldenrod

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

              • hydrocortisone

                hydrocortisone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • ibuprofen

                hydrochlorothiazide will increase the level or effect of ibuprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • imaging agents (gadolinium)

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

              • indapamide

                hydrochlorothiazide will increase the level or effect of indapamide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • indomethacin

                hydrochlorothiazide will increase the level or effect of indomethacin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • insulin aspart

                hydrochlorothiazide decreases effects of insulin aspart by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin detemir

                hydrochlorothiazide decreases effects of insulin detemir by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin glargine

                hydrochlorothiazide decreases effects of insulin glargine by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin glulisine

                hydrochlorothiazide decreases effects of insulin glulisine by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin lispro

                hydrochlorothiazide decreases effects of insulin lispro by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin NPH

                hydrochlorothiazide decreases effects of insulin NPH by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • insulin regular human

                hydrochlorothiazide decreases effects of insulin regular human by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • isoproterenol

                isoproterenol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • ketoprofen

                hydrochlorothiazide will increase the level or effect of ketoprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • ketorolac

                hydrochlorothiazide will increase the level or effect of ketorolac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • ketorolac intranasal

                hydrochlorothiazide will increase the level or effect of ketorolac intranasal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • L-methylfolate

                hydrochlorothiazide decreases levels of L-methylfolate by increasing renal clearance. Minor/Significance Unknown.

              • levalbuterol

                levalbuterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • levobetaxolol

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

              • lornoxicam

                hydrochlorothiazide will increase the level or effect of lornoxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • magnesium chloride

                hydrochlorothiazide decreases levels of magnesium chloride by increasing renal clearance. Minor/Significance Unknown.

              • magnesium citrate

                hydrochlorothiazide decreases levels of magnesium citrate by increasing renal clearance. Minor/Significance Unknown.

              • magnesium hydroxide

                hydrochlorothiazide decreases levels of magnesium hydroxide by increasing renal clearance. Minor/Significance Unknown.

              • magnesium oxide

                hydrochlorothiazide decreases levels of magnesium oxide by increasing renal clearance. Minor/Significance Unknown.

              • magnesium sulfate

                hydrochlorothiazide decreases levels of magnesium sulfate by increasing renal clearance. Minor/Significance Unknown.

              • maitake

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

              • meclofenamate

                hydrochlorothiazide will increase the level or effect of meclofenamate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • mefenamic acid

                hydrochlorothiazide will increase the level or effect of mefenamic acid by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • melatonin

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

              • meloxicam

                hydrochlorothiazide will increase the level or effect of meloxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • memantine

                hydrochlorothiazide will increase the level or effect of memantine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • mesalamine

                hydrochlorothiazide will increase the level or effect of mesalamine by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • metaproterenol

                metaproterenol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • metformin

                hydrochlorothiazide will increase the level or effect of metformin by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

                hydrochlorothiazide decreases effects of metformin by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • methotrexate

                hydrochlorothiazide increases toxicity of methotrexate by decreasing elimination. Minor/Significance Unknown. Increased myelosuppression.

              • methylprednisolone

                methylprednisolone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • metipranolol ophthalmic

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

              • metolazone

                hydrochlorothiazide will increase the level or effect of metolazone by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • midodrine

                hydrochlorothiazide will increase the level or effect of midodrine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • miglitol

                hydrochlorothiazide decreases effects of miglitol by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • minoxidil

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

              • nabumetone

                hydrochlorothiazide will increase the level or effect of nabumetone by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • naproxen

                hydrochlorothiazide will increase the level or effect of naproxen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • nateglinide

                hydrochlorothiazide decreases effects of nateglinide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • neostigmine

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

              • noni juice

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

                noni juice increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Minor/Significance Unknown.

              • norepinephrine

                norepinephrine, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

                hydrochlorothiazide decreases effects of norepinephrine by pharmacodynamic antagonism. Minor/Significance Unknown. May decrease responsiveness to norepinephrine but not enough to preclude effectiveness of the pressor agent therapeutic use.

              • octacosanol

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

              • octacosanol

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

              • ofloxacin

                hydrochlorothiazide will increase the level or effect of ofloxacin by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • oxaprozin

                hydrochlorothiazide will increase the level or effect of oxaprozin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • oxazepam

                metoprolol increases effects of oxazepam by decreasing metabolism. Minor/Significance Unknown.

              • parecoxib

                hydrochlorothiazide will increase the level or effect of parecoxib by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • penicillin G aqueous

                hydrochlorothiazide increases levels of penicillin G aqueous by decreasing renal clearance. Minor/Significance Unknown.

              • penicillin VK

                hydrochlorothiazide increases levels of penicillin VK by decreasing renal clearance. Minor/Significance Unknown.

              • physostigmine

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

              • pilocarpine

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

              • pioglitazone

                hydrochlorothiazide decreases effects of pioglitazone by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • piperacillin

                hydrochlorothiazide increases levels of piperacillin by decreasing renal clearance. Minor/Significance Unknown.

              • pirbuterol

                pirbuterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • piroxicam

                hydrochlorothiazide will increase the level or effect of piroxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • prednisolone

                prednisolone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • prednisone

                prednisone, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • quinine

                hydrochlorothiazide will increase the level or effect of quinine by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • reishi

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

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

              • repaglinide

                hydrochlorothiazide decreases effects of repaglinide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • shepherd's purse

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

              • rose hips

                rose hips will increase the level or effect of hydrochlorothiazide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • rosiglitazone

                hydrochlorothiazide decreases effects of rosiglitazone by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • salicylates (non-asa)

                hydrochlorothiazide will increase the level or effect of salicylates (non-asa) by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • salmeterol

                salmeterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

              • salsalate

                hydrochlorothiazide will increase the level or effect of salsalate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • saxagliptin

                hydrochlorothiazide decreases effects of saxagliptin by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • shepherd's purse

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

              • sitagliptin

                hydrochlorothiazide decreases effects of sitagliptin by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • sulfadiazine

                hydrochlorothiazide increases levels of sulfadiazine by unspecified interaction mechanism. Minor/Significance Unknown.

              • sulfamethoxazole

                sulfamethoxazole will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

                hydrochlorothiazide increases levels of sulfamethoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

                hydrochlorothiazide, sulfamethoxazole. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Risk of hyponatremia.

              • sulfasalazine

                hydrochlorothiazide will increase the level or effect of sulfasalazine by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • sulfisoxazole

                hydrochlorothiazide increases levels of sulfisoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

              • sulindac

                hydrochlorothiazide will increase the level or effect of sulindac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • terbutaline

                terbutaline, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.

                hydrochlorothiazide, terbutaline. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Additive hypokalemic effects.

              • tizanidine

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

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

              • tolazamide

                hydrochlorothiazide decreases effects of tolazamide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • treprostinil

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

              • tolbutamide

                hydrochlorothiazide decreases effects of tolbutamide by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • tolfenamic acid

                hydrochlorothiazide will increase the level or effect of tolfenamic acid by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • tolmetin

                hydrochlorothiazide will increase the level or effect of tolmetin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • treprostinil

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

              • triamcinolone acetonide injectable suspension

                triamcinolone acetonide injectable suspension, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypokalemia, especially with strong glucocorticoid activity.

              • triamterene

                hydrochlorothiazide will increase the level or effect of triamterene by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • trilostane

                trilostane, hydrochlorothiazide. Other (see comment). Minor/Significance Unknown. Comment: Trilostane reduces K+ loss while maintaining the natriuretic effect. Mechanism: inhibition of mineralocorticoid steroid synthesis.

              • trimethoprim

                hydrochlorothiazide will increase the level or effect of trimethoprim by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

                hydrochlorothiazide, trimethoprim. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Risk of hyponatremia.

              • valganciclovir

                hydrochlorothiazide will increase the level or effect of valganciclovir by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • verapamil

                hydrochlorothiazide will increase the level or effect of verapamil by basic (cationic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • verteporfin

                hydrochlorothiazide, verteporfin. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Increased phototoxicity.

              • vildagliptin

                hydrochlorothiazide decreases effects of vildagliptin by pharmacodynamic antagonism. Minor/Significance Unknown. Thiazide dosage >50 mg/day may increase blood glucose.

              • willow bark

                hydrochlorothiazide will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

              • yohimbe

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

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              Adverse Effects

              No adverse effects specific to combination have been observed; adverse effects limited to those previously reported with metoprolol tartrate and hydrochlorothiazide

              1-10%

              Metoprolol tartrate

              • Bradycardia (3%), cold extremities(1%), constipation (1%), depression (5%), diarrhea (5%), dizziness (10%), dyspepsia (1%), dyspnea (3%), fatigue (10%), headache (10%), heart failure (1%), hypokalemiahypotension (1%), influenza-like symptomsnausea (1%), pruritus (5%), wheezing (1%)

              Hydrochlorothiazide

              • Anorexia, epigastric distress, hypokalemia, hypotension, phototoxicity

              Frequency Not Defined

              Metoprolol tartrate

              • Bronchospasm, mask symptoms of hypoglycemia

              Hydrochlorothiazide

              • Anaphylaxis, anemia, confusion, erythema multiforme skin reactions including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis, hypomagnesemia, hyponatremia, hypochloremia, dizziness, fatigue, headache, hypercalcemia, hyperuricemia, hyperglycemia, hyperlipidemia, hypercholesterolemia, muscle weakness or cramps, nausea, purpura, rash, vertigo, vomiting

              Postmarketing Reports

              Hydrochlorothiazide

              • Non-melanoma skin cancer
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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 weeks 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

              Anuria

              Cardiogenic shock

              CHF

              Heart block 2°/3°

              Hypersensitivity to either component or sulfonamides

              Overt cardiac failure

              Sick sinus syndrome (unless permanent pacemaker in place)

              Severe peripheral vascular disease

              Sinus bradycardia

              Cautions

              Anesthesia/surgery (myocardial depression); chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures

              Avoid abrupt withdrawal

              Acute transient myopia and acute angle-closure glaucoma has been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)

              Instruct patients to protect skin from sun and undergo regular skin cancer screening

              Bronchospastic disease

              Cerebrovascular insufficiency

              Cardiomegaly

              DM, fluid or electrolyte imbalance, hyperuricemia or gout, SLE

              Hyperthyroidism or thyrotoxicosis, liver disease

              May aggravate digitalis toxicity

              Peripheral vascular disease

              Pheochromocytoma

              Renal impairment

              Risk of male sexual dysfunction

              Sensitivity reactions may occur with or without history of allergy or asthma

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              Pregnancy & Lactation

              Pregnancy Category: C

              Lactation: excreted in breast milk, use caution

              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

              Metoprolol/hydrochlorothiazide is a fixed-combination tablet that combines a beta adrenergic receptor blocker, metoprolol tartrate (Lopressor HCT) or metoprolol succinate (Dutoprol) and a thiazide diuretic, hydrochlorothiazide

              Metoprolol is a beta-1-selective (cardioselective) adrenergic blocking agent at low doses; at higher doses, it also inhibits beta-2 adrenoreceptors in the bronchial and vascular smooth muscles

              While the mechanism of the antihypertensive effects of beta-blocking agents has not been elucidated, it may involve competitive antagonism of catecholamines at peripheral (especially cardiac) adrenergic neuron sites, leading to decreased cardiac output; a central effect leading to reduced sympathetic outflow to the periphery; and suppression of renin activity

              Hydrochlorothiazide is a thiazide diuretic that inhibits Na reabsorption in distal renal tubules resulting in increased excretion of Na+ and water, also K+ and H+ ions

              Pharmacokinetics

              In comparison to immediate-release metoprolol (tartrate), the plasma metoprolol levels following administration of metoprolol succinate (long-acting) are characterized by lower peaks, longer time to peak and significantly lower peak to trough variation

              Bioavailability: 50% (metoprolol); (70%) hydrochlorothiazide

              Peak plasma concentration: 10-12 hr (metoprolol succinate); 2 hr (hydrochlorothiazide)

              Peak plasma time: 1.5-2 hr (metoprolol tartrate); 1.5-2.5 hr (hydrochlorothiazide)

              Onset: Initial diuresis from hydrochlorothiaizde (2 hr); antihypertensive effect: 3-4 days

              Duration: 3-6 hr (metoprolol tartrate); 6-12 hr (hydrochlorothiazide)

              Half-Life: 9-12 hr (metoprolol); 6-15 hr (hydrochlorothiazide)

              Clearance: hydrochlorothiazide 335 mL/min (hydrochlorothiazide)

              Excretion: Urine 95% (metoprolol) and 50-70% (hydrochlorothiazide)

              Dialyzable: No (hydrochlorothiazide)

              Distribution

              • Protein Bound: 12% (metoprolol); 40% (hydrochlorothiazide)
              • Vd: 5.6 L/kg (metoprolol); 3-4 L/kg (hydrochlorothiazide)

              Metabolism

              • Metoprolol: hepatic CYP2D6
              • Hydrochlorothiazide minimally metabolized
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              Images

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              Patient Handout

              A Patient Handout is not currently available for this monograph.
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              Formulary

              FormularyPatient Discounts

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              Tier Description
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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.