CHLORTHALIDONE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

CHLORTHALIDONE (UNII: Q0MQD1073Q) (CHLORTHALIDONE - UNII:Q0MQD1073Q)

Available from:

Mylan Pharmaceuticals Inc.

INN (International Name):

CHLORTHALIDONE

Composition:

CHLORTHALIDONE 25 mg

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

Diuretics such as chlorthalidone are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Chlorthalidone is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Chlorthalidone has also been found useful in edema due to various forms of renal dysfunction, such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developed toxemia. Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. Chlorthalidone is indicated in pregnancy when edema is due to pathologic causes, just as it is in the absence of pregnancy (however, see PRECAUTIONS, below). Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy that is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but that is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort that is not relieved by rest. In these cases, a short course of diuretics may provide relief and be appropriate. Anuria. Known hypersensitivity to chlorthalidone or other sulfonamide-derived drugs.

Product summary:

Chlorthalidone Tablets, USP are available containing 25 mg or 50 mg of chlorthalidone, USP. The 25 mg tablets are light yellow, round, unscored tablets debossed with M35 on one side of the tablet and blank on the other side. They are available as follows: NDC 0378-0222-01 bottles of 100 tablets NDC 0378-0222-10 bottles of 1000 tablets The 50 mg tablets are light green, round, scored tablets debossed with M to the left of the score and 75 to the right of the score on one side of the tablet and blank on the other side. They are available as follows: NDC 0378-0213-01 bottles of 100 tablets NDC 0378-0213-10 bottles of 1000 tablets Store at 20° to 25°C (68° to 77°F). [See USP for Controlled Room Temperature.] Protect from light. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Authorization status:

Abbreviated New Drug Application

Summary of Product characteristics

CHLORTHALIDONE- CHLORTHALIDONE TABLET
MYLAN PHARMACEUTICALS INC.
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DESCRIPTION
Chlorthalidone an oral antihypertensive/diuretic. It is a monosulfamyl
diuretic that differs
chemically from thiazide diuretics in that a double-ring system is
incorporated in its
structure. It is
2-Chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl)benzenesulfonamide with the
following structural formula:
Chlorthalidone, USP is practically insoluble in water, in ether, and
in chloroform; soluble in
methanol; slightly soluble in ethanol.
Chlorthalidone tablets are available containing either 15 mg, 25 mg or
50 mg of
chlorthalidone, USP and the following inactive ingredients: colloidal
silicon dioxide,
microcrystalline cellulose, pregelatinized starch (corn), sodium
starch glycolate (potato)
and stearic acid. The 25 mg tablets also contain D&C Yellow No. 10
Aluminum Lake and
the 50 mg tablets also contain D&C Yellow No. 10 Aluminum Lake and
FD&C Blue No.1
Aluminum Lake.
CLINICAL PHARMACOLOGY
Chlorthalidone is an oral diuretic with prolonged action (48-72 hours)
and low toxicity.
The major portion of the drug is excreted unchanged by the kidneys.
The diuretic effect
of the drug occurs in approximately 2.6 hours and continues for up to
72 hours. The
mean half-life following a 50 to 200 mg dose is 40 hours. In the first
order of absorption,
the elimination half-life is 53 hours following a 50 mg dose, and 60
hours following a 100
mg dose. Approximately 75 percent of the drug is bound to plasma
proteins, 58 percent
of the drug being bound to albumin. This is caused by an increased
affinity of the drug
to erythrocyte carbonic anhydrase. Nonrenal routes of elimination have
yet to be
clarified. Data are not available regarding percentage of dose as
unchanged drug and
metabolites, concentration of the drug in body fluids, degree of
uptake by a particular
organ or in the fetus, or passage across the blood-brain barrier.
The drug produces copious diuresis with greatly increased excretion of
sodium and
chloride. At maximal therapeutic dosage, chlor