Medication reference

Hydrochlorothiazide

Thiazide Diuretic [EPC] — ORAL

Hydrochlorothiazide — Thiazide Diuretic [EPC]. INDICATIONS & USAGE INZIRQO™ (hydrochlorothiazide) is a thiazide diuretic indicated for: The treatment of hypertension in adult and pediatric patients

Hydrochlorothiazide

Brand names

HydrochlorothiazideHYDROCHLOROTHIAZIDEhydrochlorothiazideINZIRQO

Active ingredients

HYDROCHLOROTHIAZIDE

Indications

INDICATIONS & USAGE INZIRQO™ (hydrochlorothiazide) is a thiazide diuretic indicated for: The treatment of hypertension in adult and pediatric patients alone or in combination with other antihypertensive agents, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarction (1.1). The treatment of edema associated with congestive heart failure, hepatic cirrhosis and renal disease including the nephrotic syndrome in adult and pediatric patients. (1.2). 1.1 Hypertension INZIRQO is indicated for the treatment of hypertension in adult and pediatric patients, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes., including the class to which this drug principally belongs. Control of high blood pressure should be part of comprehensive cardiovascular risk management including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. INZIRQO can be used alone or in combination with other antihypertensive agents. 1.2 Edema Treatment of edema associated with congestive heart failure, hepatic cirrhosis, and renal disease including the nephrotic syndrome in adult and pediatric patients.

Dosage

DOSAGE AND ADMINISTRATION Therapy should be individualized according to patient response. Use the smallest dosage necessary to achieve the required response. Adults For Edema The usual adult dosage is 25 mg to 100 mg daily as a single or divided dose. Many patients with edema respond to intermittent therapy, i.e., administration on alternate days or on 3 to 5 days each week. With an intermittent schedule, excessive response and the resulting undesirable electrolyte imbalance are less likely to occur. For Control of Hypertension The usual initial dose in adults is 25 mg daily given as a single dose. The dose may be increased to 50 mg daily, given as a single or two divided doses. Doses above 50 mg are often associated with marked reductions in serum potassium (see also PRECAUTIONS ). Patients usually do not require doses in excess of 50 mg of hydrochlorothiazide daily when used concomitantly with other antihypertensive agents. Infants and Children For Diuresis and For Control of Hypertension The usual pediatric dosage is 0.5 mg to 1 mg per pound (1 to 2 mg/kg) per day in single or two divided doses, not to exceed 37.5 mg per day in infants up to 2 years of age or 100 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 1.5 mg per pound (3 mg/kg) per day in two divided doses may be required (see PRECAUTIONS , Pediatric Use ). Adults For Edema The usual adult dosage is 25 mg to 100 mg daily as a single or divided dose. Many patients with edema respond to intermittent therapy, i.e., administration on alternate days or on 3 to 5 days each week. With an intermittent schedule, excessive response and the resulting undesirable electrolyte imbalance are less likely to occur. For Control of Hypertension The usual initial dose in adults is 25 mg daily given as a single dose. The dose may be increased to 50 mg daily, given as a single or two divided doses. Doses above 50 mg are often associated with marked reductions in serum potassium (see also PRECAUTIONS ). Patients usually do not require doses in excess of 50 mg of hydrochlorothiazide daily when used concomitantly with other antihypertensive agents. For Edema The usual adult dosage is 25 mg to 100 mg daily as a single or divided dose. Many patients with edema respond to intermittent therapy, i.e., administration on alternate days or on 3 to 5 days each week. With an intermittent schedule, excessive response and the resulting undesirable electrolyte imbalance are less likely to occur. For Control of Hypertension The usual initial dose in adults is 25 mg daily given as a single dose. The dose may be increased to 50 mg daily, given as a single or two divided doses. Doses above 50 mg are often associated with marked reductions in serum potassium (see also PRECAUTIONS ). Patients usually do not require doses in excess of 50 mg of hydrochlorothiazide daily when used concomitantly with other antihypertensive agents. Infants and Children For Diuresis and For Control of Hypertension The usual pediatric dosage is 0.5 mg to 1 mg per pound (1 to 2 mg/kg) per day in single or two divided doses, not to exceed 37.5 mg per day in infants up to 2 years of age or 100 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 1.5 mg per pound (3 mg/kg) per day in two divided doses may be required (see PRECAUTIONS , Pediatric Use ). For Diuresis and For Control of Hypertension The usual pediatric dosage is 0.5 mg to 1 mg per pound (1 to 2 mg/kg) per day in single or two divided doses, not to exceed 37.5 mg per day in infants up to 2 years of age or 100 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 1.5 mg per pound (3 mg/kg) per day in two divided doses may be required (see PRECAUTIONS , Pediatric Use ).

Warnings

WARNINGS AND PRECAUTIONS Monitor kidney function periodically (5.1) Monitor and correct serum electrolytes prior to use and monitor periodically (5.2). Monitor blood sugar, lipid levels, uric acid and calcium levels periodically. (5.3) Exacerbation or activation of systemic lupus erythematosus (5.4) Acute angle-closure glaucoma and acute myopia (5.5) 5.1 Impaired Renal Function Monitor kidney function periodically. Diuretics can cause hypovolemia which may precipitate acute kidney injury. Patients with chronic kidney disease, heart failure, or volume depletion may be at particular risk of developing acute renal failure on INZIRQO. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in kidney function while on INZIRQO. 5.2 Electrolyte Abnormalities INZIRQO can cause potentially symptomatic hypokalemia, hyponatremia, hypomagnesemia, and hypochloremic alkalosis. Hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion. Hypokalemia is dose dependent. Monitor and correct serum electrolytes prior to use and monitor periodically. Discontinue INZIRQO if hypokalemia is associated with clinical symptoms (e.g., ECG changes, muscular weakness). 5.3 Metabolic Disturbances INZIRQO may increase blood sugar levels, affect diabetes control, and cause changes in the need for diabetes medication. INZIRQO may raise serum levels of cholesterol and triglycerides. Monitor blood sugar and lipid levels. INZIRQO may raise the serum uric acid level due to reduced clearance of uric acid and may cause or exacerbate hyperuricemia and precipitate gout in susceptible patients. Increases in serum uric acid are dose related. INZIRQO decreases urinary calcium excretion and may cause elevations of serum calcium. Monitor calcium levels in patients with hypercalcemia receiving INZIRQO. Discontinue thiazides before carrying out tests for parathyroid function. 5.4 Systemic Lupus Erythematosus Thiazide diuretics have been reported to cause exacerbation or activation of systemic lupus erythematosus. 5.5 Acute Angle-Closure Glaucoma and Acute Myopia Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction resulting in acute angle closure glaucoma and elevated intraocular pressure with or without a noticeable acute myopic shift and/or choroidal effusions. Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation. Untreated acute angle-closure glaucoma may result in permanent vision loss. Discontinue drug intake. Consider prompt medical or surgical treatments if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.

Contraindications

CONTRAINDICATIONS INZIRQO is contraindicated: In patients with anuria. In patients with hypersensitivity to hydrochlorothiazide or any ingredient in INZIRQO. In patients with hypersensitivity to sulfonamide-derived drugs. Anuria (4) Hypersensitivity to hydrochlorothiazide or any ingredient in INZIRQO (4) Hypersensitivity to sulfonamide-derived drugs (4)

Drug interactions

Drug Interactions When given concurrently the following drugs may interact with thiazide diuretics. Alcohol, barbiturates or narcotics -potentiation of orthostatic hypotension may occur. Antidiabetic drugs -(oral agents and insulin)- dosage adjustment of the antidiabetic drug may be required. Other antihypertensive drugs -additive effect or potentiation. Cholestyramine and colestipol resins -Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85 and 43 percent, respectively. Corticosteroids, ACTH -intensified electrolyte depletion, particularly hypokalemia. Pressor amines (e.g., norepinephrine) -possible decreased response to pressor amines but not sufficient to preclude their use. Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine) -possible increased responsiveness to the muscle relaxant. Lithium-generally should not be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Refer to the package insert for lithium preparations before use of such preparations with Hydrochlorothiazide. Non-steroidal Anti-inflammatory Drugs -In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Therefore, when Hydrochlorothiazide and non-steroidal anti-inflammatory agents are used concomitantly the patient should be observed closely to determine if the desired effect of the diuretic is obtained. Drug/Laboratory Test Interactions Thiazides should be discontinued before carrying out tests for parathyroid function (see PRECAUTIONS , General) Carcinogenesis, Mutagenesis, Impairment of Fertility Two-year feeding studies in mice and rats conducted under the auspices of the National Toxicology Program (NTP) uncovered no evidence of a carcinogenic potential of hydrochlorothiazide in female mice (at doses of up to approximately 600 mg/kg/day) or in male and female rats (at doses of up to approximately 100 mg/kg/day). The NTP, however, found equivocal evidence for hepatocarcinogenicity in male mice. Hydrochlorothiazide was not genotoxic in vitro in the Ames mutagenicity assay of Salmonella typhimurium strains TA 98, TA100, TA 1535, TA 1537, and TA 1538 and in the Chinese Hamster Ovary (CHO) test for chromosomal aberrations, or in vivo in assays using mouse germinal cell chromosomes, Chinese hamster bone marrow chromosomes, and the Drosophila sex-linked recessive lethal trait gene. Positive test results were obtained only in the in vitro CHO Sister Chromatid Exchange (clastogenicity) and in the Mouse Lymphoma Cell (mutagenicity) assays, using concentrations of hydrochlorothiazide from 43 to 1300 mcg/mL, and in the Aspergillus nidulans non-disjunction assay at an unspecified concentration. Hydrochlorothiazide had no adverse effects on the fertility of mice and rats of either sex in studies wherein these species were exposed, via their diet, to doses of up to 100 and 4 mg/kg, respectively, prior to conception and throughout gestation.

Adverse reactions

ADVERSE REACTIONS The following adverse reactions have been reported and, within each category, are listed in order of decreasing severity. Body as a Whole Weakness. Cardiovascular Hypotension including orthostatic hypotension (may be aggravated by alcohol, barbiturates, narcotics or antihypertensive drugs). Digestive Pancreatitis, jaundice (intrahepatic cholestatic jaundice), diarrhea, vomiting, sialadenitis, cramping, constipation, gastric irritation, nausea, anorexia. Hematologic Aplastic anemia, agranulocytosis, leucopenia, hemolytic anemia, thrombocytopenia. Hypersensitivity Anaphylactic reactions, necrotizing angiitis (vasculitis and cutaneous vasculitis), respiratory distress including pneumonitis and pulmonary edema, photosensitivity, fever, urticaria, rash, purpura. Metabolic Electrolyte imbalance (see PRECAUTIONS ), hyperglycemia, glycosuria, hyperuricemia Musculoskeletal Muscle spasm. Nervous System/Psychiatric Vertigo, paresthesias, dizziness, headache, restlessness. Renal Renal failure, renal dysfunction, interstitial nephritis (see WARNINGS ) Skin Erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis, alopecia. Special Senses Transient blurred vision, xanthopsia. Urogenital Impotence. Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn. Postmarketing Experience Non-melanoma Skin Cancer Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses. The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥50,000 mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year. CALL YOUR DOCTOR FOR MEDICAL ADVICE ABOUT SIDE EFFECTS. YOU MAY REPORT SIDE EFFECTS TO THE FDA AT 1-800-FDA-1088 OR LEADING PHARMA, LLC AT 1-844-740-7500. Body as a Whole Weakness. Cardiovascular Hypotension including orthostatic hypotension (may be aggravated by alcohol, barbiturates, narcotics or antihypertensive drugs). Digestive Pancreatitis, jaundice (intrahepatic cholestatic jaundice), diarrhea, vomiting, sialadenitis, cramping, constipation, gastric irritation, nausea, anorexia. Hematologic Aplastic anemia, agranulocytosis, leucopenia, hemolytic anemia, thrombocytopenia. Hypersensitivity Anaphylactic reactions, necrotizing angiitis (vasculitis and cutaneous vasculitis), respiratory distress including pneumonitis and pulmonary edema, photosensitivity, fever, urticaria, rash, purpura. Metabolic Electrolyte imbalance (see PRECAUTIONS ), hyperglycemia, glycosuria, hyperuricemia Musculoskeletal Muscle spasm. Nervous System/Psychiatric Vertigo, paresthesias, dizziness, headache, restlessness. Renal Renal failure, renal dysfunction, interstitial nephritis (see WARNINGS ) Skin Erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis, alopecia. Special Senses Transient blurred vision, xanthopsia. Urogenital Impotence. Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn. Postmarketing Experience Non-melanoma Skin Cancer Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses. The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥50,000 mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year. CALL YOUR DOCTOR FOR MEDICAL ADVICE ABOUT SIDE EFFECTS. YOU MAY REPORT SIDE EFFECTS TO THE FDA AT 1-800-FDA-1088 OR LEADING PHARMA, LLC AT 1-844-740-7500.

Mechanism of action

CLINICAL PHARMACOLOGY Hydrochlorothiazide blocks the reabsorption of sodium and chloride ions, and it thereby increases the quantity of sodi­um traversing the distal tubule and the volume of water excret­ed. A portion of the additional sodium presented to the distal tubule is exchanged there for potassium and hydrogen ions. With continued use of hydro­chlorothiazide and depletion of sodium, compensatory mecha­nisms tend to increase this exchange and may produce excessive loss of potassium, hydrogen and chloride ions. Hydrochlorothiazide also decreases the excretion of cal­cium and uric acid, may increase the excretion of iodide and may reduce glomerular fil­tration rate. Metabolic toxicities associated with excessive elec­trolyte changes caused by hydrochlorothiazide have been shown to be dose-related. Pharmacokinetics and Metabolism: Hydrochlorothiazide is well absorbed (65% to 75%) fol­lowing oral administration. Absorption of hydrochlorothi­azide is reduced in patients with congestive heart failure. Peak plasma concentrations are observed within 1 to 5 hours of dosing and range from 70 to 490 ng/mL follow­ing oral doses of 12.5 to 100 mg. Plasma concentra­tions are linearly related to the administered dose. Concen­trations of hydrochlorothiazide are 1.6 to 1.8 times higher in whole blood than in plasma. Binding to serum proteins has been reported to be approxi­mately 40% to 68%. The plas­ma elimination half-life has been reported to be 6 to 15 hours. Hydrochlorothiazide is eliminated primarily by renal pathways. Following oral doses of 12.5 to 100 mg, 55% to 77% of the administered dose appears in urine and greater than 95% of the absorbed dose is excreted in urine as unchanged drug. In patients with renal disease, plasma con­centrations of hydrochlorothi­azide are increased and the elimination half-life is pro­longed. When hydrochloro­thiazide is adminis­tered with food, its bioavailabil­ity is reduced by 10%, the max­imum plasma concentration is reduced by 20%, and the time to maximum concentration increases from 1.6 to 2.9 hours. Pharmacodynamics: Acute antihypertensive effects of thi­azides are thought to result from a reduction in blood vol­ume and cardiac output, sec­ondary to a natriuretic effect, although a direct vasodilatory mechanism has also been pro­posed. With chronic adminis­tration, plasma volume returns toward normal, but peripheral vascular resistance is de­creased. The exact mechanism of the antihypertensive effect of hydrochlorothiazide is not known. Thiazides do not affect normal blood pressure. Onset of action occurs within 2 hours of dos­ing, peak effect is observed at about 4 hours, and activity per­sists for up to 24 hours. Clinical Studies: In an 87 patient 4-week double-blind, placebo controlled, parallel group trial, patients who received hydrochloro­thiazide had reductions in seated systolic and diastolic blood pressure that were significantly greater than those seen in patients who received placebo. In published placebo-controlled trials com­paring 12.5 mg of hydrochlorothiazide to 25 mg, the 12.5 mg dose preserved most of the placebo-corrected blood pressure reduction seen with 25 mg.

Available forms (6)

NDC examples

50090-693165862-13365862-13450090-698750228-11150228-11271335-964772189-51382868-01670518-255050090-505750090-7772

Indicated ICD-10 codes

Source: openFDA + RxNorm · 2026

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