hydralazine/hydrochlorothiazide (Rx)

Brand and Other Names:Hydra-Zide

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

hydralazine/hydrochlorothiazide

capsule

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

Hypertension

Not for initial therapy

Usual dose: 25 mg/25 mg PO q12hr

Maximum: 100 mg/50 mg PO q12hr

Dosage strength determined by individual titration

Renal Impairment

Use caution in dosing/titrating patients with renal dysfunction

Cumulative effects of thiazides may develop with impaired renal function; dose adjustment may be necessary; azotemia may be precipitated

Hepatic Impairment

Not studied

Administration

Dosage adjustment may be required in geriatrics

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

<18 years: Safety/efficacy not established

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Interactions

Interaction Checker

and hydralazine/hydrochlorothiazide

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              • 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.

              • carbamazepine

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

              • 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.

              • dofetilide

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

              • isocarboxazid

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

              • lofexidine

                lofexidine, hydralazine. 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, 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.

              • lonafarnib

                hydralazine will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.

              • 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.

              • pexidartinib

                hydralazine and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.

              • pretomanid

                hydralazine, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.

              • squill

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

              Monitor Closely (222)

              • acebutolol

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

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

              • aceclofenac

                aceclofenac decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • acemetacin

                acemetacin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. 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.

              • aldesleukin

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

              • albuterol

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

              • aldesleukin

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

              • amifostine

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

                amifostine, 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.

              • amiloride

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

              • aspirin

                aspirin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • amiodarone

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

              • amoxicillin

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

              • arformoterol

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

              • aspirin

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

              • 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 hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • aspirin/citric acid/sodium bicarbonate

                aspirin/citric acid/sodium bicarbonate decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • atenolol

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

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

              • atogepant

                hydralazine will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              • avanafil

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

              • avanafil

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

              • axitinib

                hydralazine increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              • beclomethasone, inhaled

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

              • 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.

              • benzphetamine

                hydralazine, benzphetamine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • betaxolol

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

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

              • bisoprolol

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

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

              • bretylium

                hydralazine, 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

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

              • carbidopa

                carbidopa increases effects of hydralazine 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.

              • 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.

              • 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.

              • candesartan

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

              • 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

                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.

              • carvedilol

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

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

                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 decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. 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.

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

              • chlorothiazide

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

              • chlorthalidone

                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

                choline magnesium trisalicylate decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • citalopram

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

              • cornsilk

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

              • corticotropin

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

              • cyclopenthiazide

                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.

              • deflazacort

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

              • dexfenfluramine

                hydralazine, dexfenfluramine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • dexmethylphenidate

                hydralazine, dexmethylphenidate. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • dextroamphetamine

                hydralazine, dextroamphetamine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • 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.

                diclofenac decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • dicloxacillin

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

              • diethylpropion

                hydralazine, diethylpropion. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • diflunisal

                diflunisal decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • digoxin

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

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

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

              • dobutamine

                hydralazine, dobutamine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • dobutamine

                dobutamine and hydrochlorothiazide both decrease serum potassium. 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.

              • dopamine

                hydralazine, dopamine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • dopexamine

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

              • drospirenone

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

              • 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

                hydralazine, ephedrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

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

              • epinephrine

                hydralazine, epinephrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

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

              • epinephrine racemic

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

              • epoprostenol

                epoprostenol, hydralazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.

              • eprosartan

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

              • esmolol

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

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

              • ethacrynic acid

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

              • etodolac

                etodolac decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • etodolac

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

              • 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.

              • fenfluramine

                hydralazine, fenfluramine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • fenoldopam

                fenoldopam, hydralazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.

              • fenoprofen

                fenoprofen decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

                fenoprofen increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. 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).

              • finerenone

                hydralazine will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.

              • 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).

              • flibanserin

                hydralazine will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.

              • flurbiprofen

                flurbiprofen decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • formoterol

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

              • ibuprofen

                ibuprofen decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • furosemide

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

              • gentamicin

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

              • ibuprofen

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

              • ibuprofen IV

                ibuprofen IV decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

                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.

              • iloprost

                hydralazine, iloprost. Either increases effects of the other by pharmacodynamic synergism. 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.

              • indapamide

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

              • indomethacin

                indomethacin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • insulin degludec

                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.

              • isavuconazonium sulfate

                hydralazine will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              • insulin degludec/insulin aspart

                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

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

              • isocarboxazid

                hydralazine, isocarboxazid. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • isoproterenol

                hydralazine, isoproterenol. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

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

              • ivacaftor

                hydralazine increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .

              • 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.

              • ketoprofen

                ketoprofen decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • ketorolac

                ketorolac decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. 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 hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • labetalol

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

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

              • lemborexant

                hydralazine will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

              • levalbuterol

                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 hydralazine 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.

              • linezolid

                hydralazine, linezolid. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • 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.

              • lisdexamfetamine

                hydralazine, lisdexamfetamine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • lithium

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

              • lomitapide

                hydralazine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

              • lornoxicam

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

                lornoxicam decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • losartan

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

              • meclofenamate

                meclofenamate decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • lurasidone

                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).

              • meclofenamate

                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.

                mefenamic acid decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • meloxicam

                meloxicam decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • metaproterenol

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

              • methamphetamine

                hydralazine, methamphetamine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • methoxsalen

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

              • methylenedioxymethamphetamine

                hydralazine, methylenedioxymethamphetamine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • methylphenidate

                hydralazine, methylphenidate. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • methylphenidate transdermal

                methylphenidate transdermal decreases effects of hydrochlorothiazide by anti-hypertensive channel blocking. Use Caution/Monitor.

              • metolazone

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

              • metoprolol

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

                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.

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

              • midazolam intranasal

                hydralazine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

              • mometasone inhaled

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

              • midodrine

                hydralazine, midodrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • minoxidil

                hydralazine, minoxidil. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.

              • mipomersen

                mipomersen, hydralazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

              • 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 hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • nadolol

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

                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

                naproxen decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • naproxen

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

              • nebivolol

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

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

              • nitroglycerin rectal

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

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

              • norepinephrine

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

                hydralazine, norepinephrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • 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. .

              • oxaprozin

                oxaprozin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • 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

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

              • parecoxib

                parecoxib decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • penbutolol

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

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

              • penicillin G aqueous

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

              • phendimetrazine

                hydralazine, phendimetrazine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • phenelzine

                hydralazine, phenelzine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • phentermine

                hydralazine, phentermine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • phenylephrine

                hydralazine, phenylephrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • phenylephrine PO

                hydralazine, phenylephrine PO. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • pindolol

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

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

              • pirbuterol

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

              • piroxicam

                piroxicam decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • piroxicam

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

              • pivmecillinam

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

              • 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.

              • potassium chloride

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

              • potassium citrate

                potassium citrate increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. 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.

              • procainamide

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

              • procarbazine

                hydralazine, procarbazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

              • propranolol

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

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

              • propylhexedrine

                hydralazine, propylhexedrine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • quinidine

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

              • pseudoephedrine

                hydralazine, pseudoephedrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

              • sacubitril/valsartan

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

              • salicylates (non-asa)

                salicylates (non-asa) decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

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

              • salmeterol

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

              • salsalate

                salsalate decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • salsalate

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

              • serdexmethylphenidate/dexmethylphenidate

                hydralazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

                hydralazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • shark cartilage

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

              • 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 chloride/magnesium sulfate/polyethylene glycol

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

              • 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.

              • sotalol

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

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

              • spironolactone

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

              • sulfasalazine

                sulfasalazine decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • succinylcholine

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

              • sulfasalazine

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

              • sulindac

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

                sulindac decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • tadalafil

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

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

              • tazemetostat

                hydralazine will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              • telmisartan

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

              • temocillin

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

              • terbutaline

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

              • ticarcillin

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

              • timolol

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

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

              • tinidazole

                hydralazine will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 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

                tolfenamic acid decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • tolmetin

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

                tolmetin decreases effects of hydralazine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.

              • tolvaptan

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

              • tranylcypromine

                hydralazine, tranylcypromine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.

              • 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

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

              • treprostinil

                hydralazine, treprostinil. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.

              • triamterene

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

              • trientine

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

              • 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

              • valoctocogene roxaparvovec

                hydralazine and valoctocogene roxaparvovec both increase Other (see comment). Use Caution/Monitor. Medications that may cause hepatotoxicity when combined with valoctogene roxaparvovec may potentiate the risk of elevated liver enzymes. Closely monitor these medications and consider alternative medications in case of potential drug interactions.

              • valsartan

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

              • 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 hydralazine by pharmacodynamic synergism. Use Caution/Monitor.

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

              • xylometazoline

                hydralazine, xylometazoline. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.

              • yohimbine

                hydralazine, yohimbine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects.

              Minor (159)

              • 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.

              • agrimony

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

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

              • albuterol

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

              • brimonidine

                brimonidine increases effects of hydralazine by pharmacodynamic synergism. 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.

              • budesonide

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

              • 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.

              • celiprolol

                hydralazine increases effects of celiprolol by pharmacodynamic synergism. 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.

              • 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 hydralazine 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.

              • diazoxide

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

                diazoxide, hydralazine. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.

              • diclofenac

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

              • forskolin

                forskolin increases effects of hydralazine by pharmacodynamic synergism. 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.

              • 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.

              • 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.

              • 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 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.

              • 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.

              • 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.

              • 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 hydralazine by pharmacodynamic synergism. Minor/Significance Unknown. Maitake mushroom has anti-tumor effects (animal/in vitro research).

              • 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.

              • 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.

              • 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.

              • noni juice

                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 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.

              • 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.

              • 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.

              • pyridoxine

                hydralazine decreases levels of pyridoxine by unspecified interaction mechanism. Minor/Significance Unknown.

              • pyridoxine (Antidote)

                hydralazine decreases levels of pyridoxine (Antidote) by unspecified interaction mechanism. Minor/Significance Unknown.

              • 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 hydralazine 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.

              • ruxolitinib

                hydralazine will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

              • 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.

              • ruxolitinib topical

                hydralazine will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

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

                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.

              • tizanidine

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

              • 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 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.

              • 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 hydralazine by pharmacodynamic synergism. Minor/Significance Unknown.

                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.

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              Adverse Effects

              Frequency Not Defined

              Hydralazine (Common)

              • Palpitations
              • Hypotension
              • Tachycardia
              • Headache
              • Peripheral neuropathy
              • Anorexia
              • Diarrhea
              • Nausea/vomiting
              • Dyspnea
              • Nasal congestion
              • Agranulocytosis
              • Eosinophilia
              • Leukopenia
              • Hemolytic anemia
              • Thrombocytopenia

              Hydrochlorothiazide

              • AnorexiaEpigastric distress
              • Hypotension
              • Orthostatic hypotension
              • Photosensitivity
              • Anaphylaxis
              • Anemia
              • Confusion
              • Erythema multiforme
              • Stevens-Johnson syndrome
              • Exfoliative dermatitis including toxic epidermal necrolysis
              • Hypomagnesemia
              • Dizziness
              • Headache
              • Hyperuricemia
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              Warnings

              Black Box Warnings

              Do not use fixed dose combination for intial treatment of hypertension

              Hypertension requires gradual titration according to individual patient requirements

              Reevaluate hypertension treatment as necessary

              Contraindications

              Anuria

              Hypersensitivity to either component or sulfonamides

              Coronary artery disease

              Dissecting aortic aneurysm

              Mitral valve rheumatic heart disease

              Cautions

              This fixed-combination drug is not indicated for initial therapy of hypertension; requires therapy titrated to the individual patient before fixed-combination drug therapy initiated

              May induce SLE-type syndrome (usually at doses >200 mg/day); instruct patients to report joint/chest pain or fever; consider discontinuation if occurs

              DM, fluid or electrolyte imbalance, hyperuricemia or gout, liver disease, renal disease

              May aggravate digitalis toxicity

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

              CVA, severe renal impairment, volume depletion, preexisting hypotension, concurrency with other hypotensive agents

              Discontinue slowly to avoid rapid rise in BP

              Risk of male sexual dysfunction

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

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              Pregnancy & Lactation

              Pregnancy

              Hydralazine has been used extensively and safely for the treatment of maternal hypertension during pregnancy. There are reports of neonatal asymptomatic and symptomatic thrombocytopenia and maternal and fetal lupus-like toxicity associated with the maternal use of hydralazine, but there are no reports of associated teratogenicity

              An increased risk of malformations found for thiazide diuretics; use of thiazides after first trimester does not seem to carry this risk; thiazide diuretics may, however pose metabolic risks to mother and fetus (hyponatremia, hypokalemia, thrombocytopenia, hyperglycemia), and may have a direct effect on smooth muscle, resulting in inhibition of labor

              Data from Michigan Medicaid Birth Defects Study (MMBDS) has revealed association between use of hydrochlorothiazide (HCTZ) and congenital abnormalities; between 1985 and 1992, 567 of 229,101 completed pregnancies were exposed to HCTZ at some time during first trimester, and 1,173 exposed to drug at any time during pregnancy; of the 567 pregnancies, there were 24 total and 7 cardiovascular birth defects (22 and 6 were expected, respectively); there were no observations of cleft palate, spina bifida, limb reduction, or hypospadias; the one instance of polydactyly did not achieve statistical significance; these data are consistent with association between use of HCTZ and birth defects, although other factors, including underlying disease(s) of the mother are not accounted for

              Cases of neonatal thrombocytopenia associated with antepartum administration of thiazide diuretics reported

              Lactation

              Both hydralazine and hydrochlorothiazide are excreted into human milk; hydrochlorothiazide is considered compatible with breast-feeding by American Academy of Pediatrics; however, the manufacturer recommends that due to potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue drug, taking into account importance of drug to mother

              In one case report of a woman who was taking hydralazine 50 mg three times a day, the milk to maternal serum concentration ratio was 1.4, indicating concentration of hydralazine in milk. Even so, the amount of drug exposed to nursing infant is relative small, and no adverse effects in nursing infant were observed in one case, a peak milk concentration of 125 ng/mL was observed between 4 and 12 hours after a daily dose in a woman who was taking HCTZ 50 mg/day; a simultaneously measured maternal serum HCTZ level was approximately 275 ng per mL; there were no detectable drug levels or electrolyte abnormalities in baby's blood; the authors calculated that, if a 1-month-old infant takes approximately 600 mL of milk per day, and average milk HCTZ level is approximately 80 ng per mL, the infant would be exposed to approximately 0.05 mg HCTZ daily; this should represent an insignificant amount of HCTZ to infant such that adverse effect in nursing infant are unlikely

              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

              Hydralazine/hydrochlorothiazide is a fixed-combination tablet that combines a vasodilator, hydralazine and a thiazide diuretic, hydrochlorothiazide

              Hydralazine, a direct vasodilator, dilates arterioles with little effect on veins; decreases systemic resistance

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

              Pharmacokinetics

              Hydralazine

              • Onset: 20-30 min (PO); 5-20 min (IV)
              • Half -life: 2-8 hr (normal renal function); 7-16 hr (end stage renal disease)
              • Duration: Up to 8 hr (PO); 1-4 hr (IV)
              • Excretion: Urine (14%)
              • Protein binding (85-90%)
              • Metabolism: Liver

              Hydrochlorothiazide

              • Half-Life: 6-15 hr
              • Bioavailability: 70%
              • Onset: 2 hr (diuresis); 4-6 hr (peak effect)
              • Duration: 6-12 hr (diuresis); 1 wk (HTN)
              • Vd: 3.6-7.8 L/kg
              • Peak Plasma:1.5-2.5 hr
              • Protein Bound: 68%
              • Metabolism: Minimally metabolized
              • Clearance: 335 mL/min
              • Excretion: Urine 50-70%
              • Dialyzable: No
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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

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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.