Complete SPL Sections#
SPL UNCLASSIFIED SECTION
SPL UNCLASSIFIED SECTION
Rx only
DESCRIPTION
DESCRIPTION SECTION
Hydrochlorothiazide, USP 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. Each tablet for oral administration contains 25 mg or 50 mg hydrochlorothiazide, USP. In addition, each tablet contains the following inactive ingredients: corn starch, FD&C Yellow #6, dibasic calcium phosphate, pregelatinized starch, colloidal silicon dioxide, lactose monohydrate and magnesium stearate.
CLINICAL PHARMACOLOGY
CLINICAL PHARMACOLOGY SECTION
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
INDICATIONS & USAGE SECTION
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.
CONTRAINDICATIONS
CONTRAINDICATIONS SECTION
Anuria. Hypersensitivity to this product or to other sulfonamide-derived drugs.
WARNINGS
WARNINGS SECTION
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 PRECAUTIONS, Drug Interactions ). Acute Myopia and Secondary Angle-Closure Glaucoma Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma. 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 can lead to permanent vision loss. The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible. Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.
PRECAUTIONS
PRECAUTIONS SECTION
ADVERSE REACTIONS
ADVERSE REACTIONS SECTION
The following adverse reactions have been reported and within each category, are listed in order of decreasing severity.
OVERDOSAGE
OVERDOSAGE SECTION
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 LD 50 of hydrochlorothiazide is greater than 10 g/kg in the mouse and rat.
DOSAGE AND ADMINISTRATION
DOSAGE & ADMINISTRATION SECTION
Therapy should be individualized according to patient response. Use the smallest dosage necessary to achieve the required response.
HOW SUPPLIED
HOW SUPPLIED SECTION
Hydrochlorothiazide Tablets, USP are available as light orange, circular, flat, beveled, uncoated tablets, with score line having "U" and "128" debossed across the score line on one side and plain on other side containing 25 mg of hydrochlorothiazide, USP. NDC 60760-315-30 BOTTLES OF 30 NDC 60760-315-90 BOTTLES OF 90 PHARMACIST: Dispense in a well-closed container as defined in the USP. Use child-resistant closure (as required) Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].
PRINCIPAL DISPLAY PANEL
PACKAGE LABEL.PRINCIPAL DISPLAY PANEL
