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a thiazide diuretic used as an antihypertensive agent and for treatment of edema.


Apo-Hydro (CA), Diuchlor H (CA), Hydro-Par, Microzide, Neo-Codema (CA), Novo-Hydrazide (CA), PMS-Hydrochlorothiazide (CA), Urozide (CA)

Pharmacologic class: Thiazide diuretic

Therapeutic class: Diuretic, antihypertensive

Pregnancy risk category B


Increases sodium and water excretion by inhibiting sodium reabsorption in distal tubules; promotes excretion of chloride, potassium, magnesium, and bicarbonate. Also may produce arteriolar dilation, reducing blood pressure.


Capsules: 12.5 mg

Oral solution: 10 mg/ml, 100 mg/ml

Tablets: 12.5 mg, 25 mg, 50 mg, 100 mg

Indications and dosages

Edema caused by heart failure, renal dysfunction, cirrhosis, corticosteroid therapy, or estrogen therapy

Adults: 25 to 100 mg P.O. daily as a single dose or in divided doses. Maximum dosage is 200 mg/day.

Mild to moderate hypertension

Adults: Initially, 12.5 mg daily P.O.; then, based on blood pressure response, may give 12.5 to 50 mg/day P.O. Higher dosages may be given in refractory cases.

Children ages 2 to 12: 1 to 2 mg/kg/day P.O. in single dose or two divided doses, not to exceed 100 mg/day

Children younger than age 2: 1 to 2 mg/kg P.O. as single dose or divided doses, not to exceed 37.5 mg/day; infants less than age 6 months may require dosage of 3 mg/kg/day in two divided doses.

Off-label uses

• Hypercalcemia
• Ménière's disease


• Hypersensitivity to drug, other thiazides, sulfonamides, or tartrazine
• Renal decompensation or anuria


Use cautiously in:
• renal or severe hepatic impairment, fluid or electrolyte imbalances, gout, systemic lupus erythematosus, hyperparathyroidism, glucose tolerance abnormalities, bipolar disorder
• elderly patients
• pregnant or breastfeeding patients.


• Give with food or milk if GI upset occurs.
• Administer early in day so diuretic effect doesn't disturb sleep.

Adverse reactions

CNS: dizziness, drowsiness, lethargy, headache, insomnia, nervousness, vertigo, asthenia, asterixis, paresthesias, confusion, fatigue, encephalopathy

CV: chest pain, orthostatic hypotension, ECG changes, thrombophlebitis, arrhythmias

EENT: nystagmus

GI: nausea, vomiting, epigastric distress, anorexia, pancreatitis

GU: polyuria, nocturia, erectile dysfunction, loss of libido, renal failure

Hematologic: anemia, hemolytic anemia, agranulocytosis, leukopenia, thrombocytopenia

Hepatic: jaundice, hepatitis

Metabolic: dehydration, gout, hyperglycemia, hypokalemia, hypocalcemia, hypovolemia, hypomagnesemia, hyponatremia, hypophosphatemia, hyperuricemia, hypochloremic alkalosis

Musculoskeletal: muscle cramps

Skin: photosensitivity, urticaria, rash, dermatitis, purpura, alopecia, flushing

Other: fever, weight loss, anaphylaxis


Drug-drug.Adrenocorticotropic hormone, corticosteroids: increased risk of intensified electrolyte depletion, particularly hypokalemia

Allopurinol: increased risk of hypersensitivity reaction

Amphotericin B, corticosteroids, digoxin, mezlocillin, piperacillin, ticarcillin: increased risk of hypokalemia

Antihypertensives, barbiturates, nitrates, opioids: increased hypotension

Cholestyramine, colestipol: decreased hydrochlorothiazide absorption

Digoxin: increased risk of hypokalemia

Insulin, oral hypoglycemics: possible decreased hypoglycemic effect

Lithium: decreased excretion and increased blood level of lithium

Nondepolarizing skeletal muscle relaxants (such as tubocurarine): increased skeletal muscle relaxant effect

Nonsteroidal anti-inflammatory drugs: decreased hydrochlorothiazide efficacy

Vasopressors: decreased pressor effect

Drug-diagnostic tests.Bilirubin, blood and urine glucose (in diabetic patients), calcium, creatinine, uric acid: increased levels

Cholesterol, low-density lipoproteins, magnesium, potassium, protein-bound iodine, sodium, triglycerides, urinary calcium: decreased levels

Drug-herbs.Dandelion: interference with diuretic activity

Ginkgo: decreased antihypertensive effect

Licorice, stimulant laxative herbs (aloe, cascara sagrada, senna): increased risk of hypokalemia

Drug-behaviors.Alcohol use: increased hypotension

Sun exposure: increased risk of photo-sensitivity

Patient monitoring

• Monitor blood pressure, fluid intake and output, and daily weight.
• Assess electrolyte levels, especially potassium. Monitor for signs and symptoms of hypokalemia.
• Monitor blood urea nitrogen and creatinine levels.
• Check blood glucose level in diabetic patients.
• Assess for signs and symptoms of gout attacks in patients with gouty arthritis.

Patient teaching

• Advise patient to take with food or milk if GI upset occurs.
• Tell patient to take early in day to avoid nighttime urination.
• Instruct patient to track intermittent doses on calendar.
• Tell patient to weigh himself daily, at same time on same scale and wearing same clothes.

Instruct patient to report decreased urination, swelling, unusual bleeding or bruising, dizziness, fatigue, numbness, and muscle weakness or cramping.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure decrease.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.


A potent orally effective diuretic and antihypertensive agent related to chlorothiazide; can cause hypokalemia and hyperglycemia.


/hy·dro·chlo·ro·thi·a·zide/ (-klor″o-thi´ah-zīd) a thiazide diuretic, used for treatment of hypertension and edema.


A diuretic drug, C7H8ClN3O4S2, used in the treatment of hypertension.


a thiazide diuretic.
indications It is prescribed in the treatment of mild to moderate hypertension and edema caused by congestive heart failure or protein loss by the kidney (nephritic syndrome).
contraindications Anuria or known hypersensitivity to this drug, to other thiazide medication, or to sulfonamide derivatives prohibits its use.
adverse effects Among the more serious adverse effects are hypoglycemia, hyperglycemia, hyperuricemia, and hypersensitivity reactions.


A potent orally effective diuretic andantihypertensive agent related to chlorothiazide.


A drug used to increase the output of urine so as to relieve the body of surplus water. A thiazide DIURETIC drug. The drug is on the WHO official list. A brand name is Hydrosaluric. Hydrochlorothiazide is formulated in conjunction with a variety of drugs. It is available with potassium under the brand name Amil-Co; with another diuretic as Dyazide, Moduret 25, Moduretic, Triam-Co; with ANGIOTENSIN CONVERTING ENZYME inhibitor drugs as Accuretic, Acezide, Capozide, Carace 10 Plus, Innozide and Zestoretic 20; with BETA BLOCKER drugs as Co-Betaloc, Kalten, Moducren and Monozide 10; and with an angiotensin II antagonist drug as Cozaar-Comp.


A potent orally effective diuretic and antihypertensive agent related to chlorothiazide; can cause hypokalemia and hyperglycemia.


n brand names: Esidrix, HydroDIURIL;
drug class: thiazide diuretic;
action: acts on distal tubule by increasing excretion of water, sodium, chloride, potassium;
uses: edema, hypertension, diuresis, congestive heart failure.


a thiazide diuretic; sometimes used for an antidiuretic effect in the treatment of diabetes insipidus in dogs.
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Telmisartan plus HCTZ vs amlodipine plus HCTZ in older patients with systolic hypertension: results from a large ambulatory blood pressure monitoring study.
Further, the analysis showed treatment with OM/AML + HCTZ was effective in BP goal attainment in both obese patients and patients with diabetes.
In the Multiple Risk Factor Intervention Trial, patients given HCTZ by investigators had 44% more coronary heart disease and 16% more deaths after 5 years of follow-up, compared with control patients cared for in the community by primary care physicians (Circulation 1990;82:1616-28).
More recently, the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial found fewer cardiovascular events with chlorthalidone than with an angiotensin-converting enzyme inhibitor, while the second Australian National Blood Pressure study found an inhibitor to be superior to HCTZ at reducing combined mortality and morbidity in men but not in women.
In the olmesartan medoxomil and HCTZ fixed-dose combination group, patients were force titrated from 20/12.
The reductions were significantly greater than that of the fixed-dose combination of olmesartan medoxomil and HCTZ (37.
The 10-week, randomized, double-blind study compared the effect of CLD and HCTZ, both in combination with azilsartan medoxomil, on systolic and diastolic blood pressure (SBP, DBP) by clinic blood pressure measurement and by ambulatory blood pressure monitoring (ABPM) in 609 patients with hypertension.
In the supportive study of about 500 patients with moderate hypertension, Avalide was more effective in reducing blood pressure than either irbesartan or HCTZ alone, had a comparable safety profile, and was well tolerated in the elderly, according to BMS.
Those on combination therapy with HCTZ averaged reductions of 18.
Results from the landmark Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) "suggested that HCTZ is an excellent antihypertensive drug in a study that enrolled all comers," said Dr.
This approval gives doctors the opportunity to aggressively treat their patients with a single-pill combination of the only approved drug, Tekturna, that works by directly targeting renin and decreasing the activity of the renin angiotensin aldosterone system (RAAS) and, HCTZ, a diuretic.