displayName: DESCRIPTION SECTION
FDA Article Code: 34089-3
Hydrochlorothiazide is a diuretic and antihypertensive. It is the 3,4-dihydro derivative of chlorothiazide. It is chemically designated as 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide and has the following structural formula:
Hydrochlorothiazide, USP is a white, or practically white, crystalline powder which is slightly soluble in water, freely soluble in sodium hydroxide solution, in n-butylamine, and in dimethylformamide; sparingly soluble in methanol; insoluble in ether, in chloroform, and in dilute mineral acids.
Hydrochlorothiazide is supplied as 25 mg and 50 mg tablets for oral use. Each tablet contains the following inactive ingredients: FD&C Yellow #6 Lake, lactose monohydrate, magnesium stearate, microcrystalline cellulose, pregelatinized starch.
displayName: CLINICAL PHARMACOLOGY SECTION
FDA Article Code: 34090-1
The mechanism of the antihypertensive effect of thiazides is unknown. Hydrochlorothiazide does not usually affect normal blood pressure.
Hydrochlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosage all thiazides are approximately equal in their diuretic efficacy.
Hydrochlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate.
After oral use diuresis begins within 2 hours, peaks in about 4 hours and lasts about 6 to 12 hours.
INDICATIONS AND USAGE
displayName: INDICATIONS & USAGE SECTION
FDA Article Code: 34067-9
Hydrochlorothiazide tablets are indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.
Hydrochlorothiazide tablets have 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.
displayName: CONTRAINDICATIONS SECTION
FDA Article Code: 34070-3
Hypersensitivity to this product or to other sulfonamide-derived drugs.
displayName: WARNINGS SECTION
FDA Article Code: 34071-1
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.
Lithium generally should not be given with diuretics (see
displayName: ADVERSE REACTIONS SECTION
FDA Article Code: 34084-4
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.
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
), hyperglycemia, glycosuria, hyperuricemia.
Musculoskeletal: Muscle spasm.
Nervous System/Psychiatric: Vertigo, paresthesias, dizziness, headache, restlessness.
Renal: Renal failure, renal dysfunction, interstitial nephritis (see
Skin: Erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis, alopecia.
Special Senses: Transient blurred vision, xanthopsia.
Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn.
displayName: OVERDOSAGE SECTION
FDA Article Code: 34088-5
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. The degree to which hydrochlorothiazide is removed by hemodialysis has not been established. The oral LD50 of hydrochlorothiazide is greater than 10 g/kg in the mouse and rat.
DOSAGE AND ADMINISTRATION
displayName: DOSAGE & ADMINISTRATION SECTION
FDA Article Code: 34068-7
Therapy should be individualized according to patient response. Use the smallest dosage necessary to achieve the required response.
displayName: HOW SUPPLIED SECTION
FDA Article Code: 34069-5
NDC: 63739-128-10 10 TABLET in a BLISTER PACK
HYDROCHLOROTHIAZIDE TABLETS, USP
displayName: PACKAGE LABEL.PRINCIPAL DISPLAY PANEL
FDA Article Code: 51945-4