Overview
DESCRIPTION Chlorothiazide sodium is a diuretic and antihypertensive. It is 6-chloro- 2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide monosodium salt and its molecular weight is 317.71. Its molecular formula is C 7 H 5 ClN 3 NaO 4 S 2 and its structural formula is: Chlorothiazide sodium for injection, USP is a sterile lyophilized white powder and is supplied in a vial containing:...
Mechanism of Action
CLINICAL PHARMACOLOGY The mechanism of the antihypertensive effect of thiazides is unknown. Chlorothiazide does not usually affect normal blood pressure. Chlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosage all thiazides are approximately equal in their diuretic efficacy. Chlorothiazide 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. Following intravenous use of chlorothiazide sodium, onset of the diuretic action occurs in 15 minutes and the maximal action in 30 minutes.
Indications
- INDICATIONS AND USAGE Chlorothiazide sodium for injection is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Chlorothiazide sodium for injection has also been found useful in edema due to various forms of renal dysfunction such as nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Use in Pregnancy Routine use of diuretics during normal pregnancy is inappropriate and exposes mother and fetus to unnecessary hazard.
Common Doses
- 500 mg
- 1 g
- 18 mL
- 28 mg
Dosage
DOSAGE AND ADMINISTRATION Chlorothiazide sodium for injection should be reserved for patients unable to take oral medication or for emergency situations. Therapy should be individualized according to patient response. Use the smallest dosage necessary to achieve the required response. Intravenous use in infants and children has been limited and is not generally recommended. When medication can be taken orally, therapy with chlorothiazide tablets or oral suspension may be substituted for intravenous therapy, using the same dosage schedule as for the parenteral route.
Contraindications
- CONTRAINDICATIONS Anuria. Hypersensitivity to any component of this product or to other sulfonamide-derived drugs.
Side Effects
- 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.
Interactions
- Drug Interactions 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. Corticosteroids, ACTH - intensified electrolyte depletion, particularly hypokalemia. Pressor amines (e.g., norepinephrine) - possible decreased response to pressor amines but not sufficient to preclude their use.