Hydrochlorothiazide

Hydrochlorothiazide tablets are indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Hydrochlorothiazide has also been found useful in edema due to various forms of renal dysfunction such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Hydrochlorothiazide tablets are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs in the more severe forms of hypertension. …

• 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 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 three to five 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 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 )

• There are no well-controlled clinical trials
• In pediatric patients
• Information on dosing in this age group is supported by evidence from empiric use
• In pediatric patients and published literature regarding the treatment of hypertension in such patients. (See DOSAGE AND ADMINISTRATION , I nfants and Children )

Non-melanoma Skin Cancer: Instruct patients taking hydrochlorothiazide to protect skin from the sun and undergo regular skin cancer screening.

• Anuria
• Hypersensitivity to this product or to other sulfonamide-derived drugs

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. …

Use with caution in severe renal disease. In patients with renal disease, thiazides may precipitate azotemia. Cumulative effects of the drug may develop in patients with impaired renal function. Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma. Thiazides may add to or potentiate the action of other antihypertensive drugs. Sensitivity reactions may occur in patients with or without a history of allergy or bronchial asthma. The possibility of exacerbation or activation of systemic lupus erythematosus has been reported. …

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, leukopenia, hemolytic anemia, thrombocytopenia. …

Pregnancy Teratogenic Effects: Studies in which hydrochlorothiazide was orally administered to pregnant mice and rats during their respective periods of major organogenesis at doses up to 3,000 and 1,000 mg hydrochlorothiazide/kg, respectively, provided no evidence of harm to the fetus. There are, however, no adequate and well-controlled studies in pregnant women. …

The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis. If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias. In the event of overdosage, symptomatic and supportive measures should be employed. Emesis should be induced or gastric lavage performed. Correct dehydration, electrolyte imbalance, hepatic coma and hypotension by established procedures. If required, give oxygen or artificial respiration for respiratory impairment. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.