INDICATIONS AND USAGE 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 the nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.

Hydrochlorothiazide is 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.

WARNINGS 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.

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, 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 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.

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.

Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn.