Dosing & Uses
Dosage Forms & Strengths
methyldopa/hydrochlorothiazide
tablet
- 250mg/15mg
- 250mg/25mg
Hypertension
Not for initial therapy
Usual starting dose: 250 mg methyldopa/15-25 mg hydrochlorothiazide PO q12hr; alternatively 500 mgmethyldopa/30-50 mg hydrochlorothiazide PO qDay
Avoid hydrochlorothiazide doses >50 mg qDay
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; if CrCl < 30 mL/min avoid use; azotemia may be precipitated
Administration
To minimize dose-independent side effects, it is usually appropriate to begin combination therapy only after a patient has failed to achieve the desired effect with monotherapy
Since both components have a relatively short duration of action, withdrawal is followed by return of hypertension usually within 48 hours, not complicated by overshoot of blood pressure
<18 years: Safety/efficacy not established
Dose reduction may be necessary depending on patient's renal function
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (39)
- 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.
- aripiprazole
aripiprazole decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- benperidol
benperidol decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- carbamazepine
carbamazepine, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased risk of systemic hyponatremia.
- chlorpromazine
chlorpromazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- clozapine
clozapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- 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.
- droperidol
droperidol decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- fluphenazine
fluphenazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- haloperidol
haloperidol decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- iloperidone
iloperidone decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- iobenguane I 131
methyldopa will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.
- isocarboxazid
isocarboxazid, hydrochlorothiazide. Other (see comment). Contraindicated. Comment: Additive hypotensive effects may be seen when MAOI's are combined with antihypertensives.
- lofexidine
lofexidine, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.
lofexidine, methyldopa. 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. - loxapine
loxapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- 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.
- loxapine inhaled
loxapine inhaled decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- metoclopramide
metoclopramide decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated.
metoclopramide decreases levels of methyldopa by pharmacodynamic antagonism. Contraindicated. - metoclopramide intranasal
methyldopa, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
- olanzapine
olanzapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- paliperidone
paliperidone decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- perphenazine
perphenazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- pexidartinib
methyldopa and pexidartinib both increase inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.
- pimozide
pimozide decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- pretomanid
methyldopa, 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.
- prochlorperazine
prochlorperazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- promethazine
promethazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- quetiapine
quetiapine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- risperidone
risperidone decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- squill
hydrochlorothiazide increases toxicity of squill by Other (see comment). Avoid or Use Alternate Drug. Comment: Potassium depletion may enhance toxicity of squill.
- thioridazine
thioridazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- thiothixene
thiothixene decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
- tranylcypromine
tranylcypromine, methyldopa. Other (see comment). Avoid or Use Alternate Drug. Comment: Tranylcypromine inhibits the hypotensive effects of methyldopa. At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with methyldopa.
- tretinoin
hydrochlorothiazide, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.
- tretinoin topical
hydrochlorothiazide, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.
- trifluoperazine
trifluoperazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.
Monitor Closely (202)
- acebutolol
acebutolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- aceclofenac
aceclofenac increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- acemetacin
acemetacin increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- albiglutide
hydrochlorothiazide decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Monitor glycemic control especially when initiating, discontinuing, or increasing thiazide diuretic dose.
- albuterol
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, 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.
- 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.
- apomorphine
apomorphine and methyldopa both increase dopaminergic effects. 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/citric acid/sodium bicarbonate
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.
- avanafil
avanafil increases effects of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- beclomethasone, inhaled
beclomethasone, inhaled increases toxicity of hydrochlorothiazide by increasing elimination. Use Caution/Monitor. May increase the hypokalemic effects of thiazide diuretics.
- 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
methyldopa increases effects of benzphetamine by unknown mechanism. Use Caution/Monitor.
- betaxolol
betaxolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- bisoprolol
bisoprolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- bretylium
methyldopa, 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.
- cabergoline
cabergoline and methyldopa both increase dopaminergic effects. Use Caution/Monitor.
- buprenorphine, long-acting injection
buprenorphine, long-acting injection decreases effects of hydrochlorothiazide by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Opioids can reduce diuretic efficacy by inducing antidiuretic hormone release.
- 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.
- carbonyl iron
carbonyl iron decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- carvedilol
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 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.
- citalopram
hydrochlorothiazide, citalopram. pharmacodynamic synergism. Use Caution/Monitor. Possible additive hyponatremia.
- clonidine
clonidine, methyldopa. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Sympatholytic action may worsen sinus node dysfunction and atrioventricular (AV) block.
- 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
methyldopa increases effects of dexfenfluramine by unknown mechanism. Use Caution/Monitor.
- dexmethylphenidate
methyldopa increases effects of dexmethylphenidate by unknown mechanism. Use Caution/Monitor.
- dextroamphetamine
methyldopa increases effects of dextroamphetamine by unknown mechanism. Use Caution/Monitor.
- 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.
- dicloxacillin
dicloxacillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- diethylpropion
methyldopa increases effects of diethylpropion by unknown mechanism. Use Caution/Monitor.
- diflunisal
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
dobutamine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
methyldopa increases effects of dobutamine by unknown mechanism. 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
dopamine and methyldopa both increase dopaminergic effects. Use Caution/Monitor.
methyldopa increases effects of dopamine by unknown mechanism. Use Caution/Monitor. - 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.
- entacapone
entacapone will increase the level or effect of methyldopa by decreasing metabolism. Use Caution/Monitor. Entacapone is a COMT inhibitor. Caution if coadministered with drugs metabolized by COMT. If coadministered, monitor for changes in heart rate, heart rhythm, and blood pressure.
- ephedrine
ephedrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
methyldopa increases effects of ephedrine by unknown mechanism. Use Caution/Monitor. - epinephrine
epinephrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
methyldopa increases effects of epinephrine by unknown mechanism. Use Caution/Monitor. - epinephrine racemic
epinephrine racemic and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
- fenfluramine
methyldopa increases effects of fenfluramine by unknown mechanism. Use Caution/Monitor.
- eprosartan
eprosartan increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- esmolol
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 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.
- fenoprofen
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).
- 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).
- ferric maltol
ferric maltol decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous fumarate
ferrous fumarate decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous gluconate
ferrous gluconate decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- ferrous sulfate
ferrous sulfate decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- flurbiprofen
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.
- 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 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.
hydrochlorothiazide will increase the level or effect of ibuprofen IV by acidic (anionic) drug competition for renal tubular clearance. 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 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.
- 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.
- iron dextran complex
iron dextran complex decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- iron sucrose
iron sucrose decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- isoproterenol
isoproterenol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
methyldopa increases effects of isoproterenol by unknown mechanism. Use Caution/Monitor. - 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.
- levodopa
methyldopa, levodopa. pharmacodynamic synergism. Use Caution/Monitor. Risk of additive hypotensive effects, and risk of toxic CNS effects such as psychosis.
- ketoprofen
ketoprofen increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ketorolac
ketorolac increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ketorolac intranasal
ketorolac intranasal increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- labetalol
labetalol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- 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.
- 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.
- 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
methyldopa increases effects of lisdexamfetamine by unknown mechanism. Use Caution/Monitor.
- lisuride
lisuride and methyldopa both increase dopaminergic effects. Use Caution/Monitor.
- lithium
hydrochlorothiazide increases toxicity of lithium by decreasing elimination. Use Caution/Monitor.
- lornoxicam
lornoxicam increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- losartan
losartan increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lurasidone
lurasidone increases effects of methyldopa by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.
lurasidone increases effects of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed. - maitake
maitake increases effects of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of hypokalemia (theoretical interaction).
- methamphetamine
methyldopa increases effects of methamphetamine by unknown mechanism. Use Caution/Monitor.
- 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.
- meloxicam
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.
- methoxsalen
methoxsalen, hydrochlorothiazide. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.
- methylenedioxymethamphetamine
methyldopa increases effects of methylenedioxymethamphetamine by unknown mechanism. Use Caution/Monitor.
- methylphenidate
methyldopa increases effects of methylphenidate by unknown mechanism. Use Caution/Monitor.
- metolazone
hydrochlorothiazide and metolazone both decrease serum potassium. Use Caution/Monitor.
- metoprolol
metoprolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
hydrochlorothiazide, metoprolol. Either increases toxicity of the other by Other (see comment). Modify Therapy/Monitor Closely. Comment: May cause idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma, which can lead to permanent vision loss. - midazolam intranasal
midazolam intranasal, methyldopa. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.
- midodrine
methyldopa increases effects of midodrine by unknown mechanism. Use Caution/Monitor.
- mipomersen
mipomersen, methyldopa. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.
- mometasone inhaled
mometasone inhaled increases toxicity of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Corticosteroids may increase hypokalemic effect of loop diuretics.
- 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.
- nadolol
nadolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension.
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.
- norepinephrine
methyldopa increases effects of norepinephrine by unknown mechanism. Use Caution/Monitor.
- naproxen
naproxen increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nebivolol
nebivolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nitroglycerin rectal
nitroglycerin rectal, hydrochlorothiazide. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .
- norepinephrine
norepinephrine and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
- oliceridine
oliceridine decreases effects of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor for signs of diminished diuresis and/or effects on blood pressure and increase dosage of the diuretic as needed. .
- olmesartan
olmesartan 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.
- opicapone
opicapone will increase the level or effect of methyldopa by decreasing metabolism. Use Caution/Monitor. Opicapone is a COMT inhibitor. Caution if coadministered with drugs metabolized by COMT. If coadministered, monitor for changes in heart rate, heart rhythm, and blood pressure.
- oxaprozin
oxaprozin increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- parecoxib
parecoxib increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- penbutolol
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
methyldopa increases effects of phendimetrazine by unknown mechanism. Use Caution/Monitor.
- phentermine
methyldopa increases effects of phentermine by unknown mechanism. Use Caution/Monitor.
- phenylephrine
methyldopa increases effects of phenylephrine by unknown mechanism. Use Caution/Monitor.
- phenylephrine PO
methyldopa increases effects of phenylephrine PO by unknown mechanism. Use Caution/Monitor.
- pindolol
pindolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
pindolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension. - pirbuterol
pirbuterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
- polysaccharide iron
polysaccharide iron decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- 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.
- pramipexole
methyldopa and pramipexole both increase dopaminergic effects. Use Caution/Monitor.
- 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.
- propranolol
propranolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension.
propranolol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. - propylhexedrine
methyldopa increases effects of propylhexedrine by unknown mechanism. Use Caution/Monitor.
- quinidine
quinidine will increase the level or effect of hydrochlorothiazide by basic (cationic) drug competition for renal tubular clearance. Use Caution/Monitor.
- pseudoephedrine
methyldopa increases effects of pseudoephedrine by unknown mechanism. Use Caution/Monitor.
- ropinirole
methyldopa and ropinirole both increase dopaminergic effects. Use Caution/Monitor.
- rose hips
rose hips decreases levels of methyldopa by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
- 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) 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 increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- 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 sulfate/magnesium sulfate
sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of hydrochlorothiazide by Other (see comment). Use Caution/Monitor. Comment: Coadministration with medications that cause fluid and electrolyte abnormalities may increase the risk of adverse events of seizure, arrhythmias, and renal impairment.
- sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol
hydrochlorothiazide and sodium sulfate/potassium sulfate/magnesium sulfate/polyethylene glycol both decrease serum potassium. Modify Therapy/Monitor Closely.
- sotalol
sotalol increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- spironolactone
spironolactone increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.
- 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.
- tadalafil
tadalafil increases effects of hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- 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.
timolol, methyldopa. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Non selective beta blocker administration during withdrawal from methyldopa may result in rebound hypertension. - tolcapone
tolcapone will increase the level or effect of methyldopa by decreasing metabolism. Use Caution/Monitor. Tolcapone is a COMT inhibitor. Caution if coadministered with drugs metabolized by COMT. If coadministered, monitor for changes in heart rate, heart rhythm, and blood pressure.
- tolfenamic acid
tolfenamic acid increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tolmetin
tolmetin increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tolvaptan
tolvaptan increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- toremifene
hydrochlorothiazide, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.
- torsemide
torsemide and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.
- triamterene
triamterene increases and hydrochlorothiazide decreases serum potassium. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.
- 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
- 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 hydrochlorothiazide by pharmacodynamic synergism. Use Caution/Monitor.
- xylometazoline
methyldopa increases effects of xylometazoline by unknown mechanism. Use Caution/Monitor.
Minor (83)
- 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 hydrochlorothiazide by pharmacodynamic synergism. Minor/Significance Unknown.
- albuterol
albuterol, hydrochlorothiazide. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Hypokalemia.
- 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.
- 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.
- 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.
- diclofenac
hydrochlorothiazide will increase the level or effect of diclofenac by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- diflunisal
hydrochlorothiazide will increase the level or effect of diflunisal by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
- 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.
- lithium
methyldopa increases toxicity of lithium by unknown mechanism. Minor/Significance Unknown.
- lornoxicam
hydrochlorothiazide will increase the level or effect of lornoxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Methyldopa
- Angina
- Arthralgia
- Bradycardia
- Orthostatic hypotension
- Depression
- Dizziness
- Lethargy
- Sedation
- Rash, liver toxicity
- Gynecomastia
- Impotence
- Dry mouth
- Nausea/vomiting
- Hemolytic anemia
- Thrombocytopenia, lupus-like syndrome
Hydrochlorothiazide
- Anorexia
- Epigastric distress
- Hypotension
- Orthostatic hypotension
- Photosensitivity
- Anaphylaxis
- Anemia
- Confusion
- Erythema multiforme
- Stevens-Johnson syndrome
- Exfoliative dermatitis including toxic epidermal necrolysis
- Hypomagnesemia
- Dizziness
- Headache
- Hyperuricemia
Warnings
Black Box Warning
Not indicated for initial therapy of hypertension; before initiating therapy requires therapy titrated to the individual patient; if fixed combination represents determined dosage for each individual agent; use may be more convenient in patient management; treatment of hypertension must be reevaluated as conditions in each patient warrant
Contraindications
Anuria
Renal decompensation
Hypersensitivity to either component or sulfonamides
Mitral valve rheumatic heart disease
Active liver disease, such as acute hepatitis and active cirrhosis
Liver disorders previously associated with methyldopa therapy
Concomitant therapy with monoamine oxidase (MAO) inhibitors
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
DM, fluid or electrolyte imbalance, hyperuricemia or gout, liver disease, renal disease, SLE, hypotension
May aggravate digitalis toxicity
Sensitivity reactions may occur with or w/o history of allergy or asthma
Risk of male sexual dysfunction
CHF, dialysis pts (increased risk of hypertension following procedure), edema, hemolytic anemia, severe bilateral CVD
Avoid abrupt withdrawal
Risk of decreased libido and impotence in men
May impair ability to perform hazardous tasks
Tolerance develops on prolonged therapy, especially if no concurrent diuretic (methyldopa causes Na and water retention)
Acute transient myopia and acute angle-closure glaucoma has been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)
Interferes with some lab tests
Pregnancy & Lactation
Pregnancy Category: C
Lactation: both components appear in breast milk, use caution
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Hydrochlorothiazide; methyldopa combines 2 antihypertensive agents with different mechanisms to lower blood pressure; effects of hydrochlorothiazide and methyldopa on blood pressure are additive
Thiazide diuretics lower blood pressure by increasing the excretion of sodium, whereas methyldopa may lower blood pressure by stimulating central inhibitory alpha-adrenergic receptors, false neurotransmission, and/or reduction of plasma renin activity.
Pharmacokinetics
Methyldopa
- Onset: 4-6 hr (PO, IV) hypotensive effect
- Vd: 0.23 L/kg
- Protein binding: 10-15%
- Bioavailability: 42%
- Half-life: 1.5-2 hr; prolonged in end stage renal disease
- Peak plasma time: 2-4 hr
- Excretion: Urine (70%)
- Metabolism: Intestinal and hepatic
- Duration: 12-24 hr (single dose); 24-48 hr (multiple dose)
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
Images
Formulary
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