Chlorothiazide
- Atc Codes:C03AA04
- CAS Codes:7085-44-1#58-94-6
- PHARMGKB ID:7085-44-1#58-94-6
Table of contents
- Brand Names
- Chemistry
- Pharmacologic Category
- Mechanism of Action
- Therapeutic Use
- Pregnancy and Lactation Implications
- Contraindications
- Warnings and Precautions
- Adverse Reactions
- Caution and personalized dose adjustment in patients with the following genotypes
- Substrate of
- Drug Interactions
- Nutrition/Nutraceutical Interactions
- Dosage
- Pharmacokinetics and Pharmacodynamics
- Special Considerations
Brand Names
North America
USA: Chlorothiazide, Diuril.
Drug combinations
Chemistry
Chlorothiazide Sodium: C~7~H~5~ClN~3~NaO~4~S~2~. Mw: 317.71. (1) 2H-1,2,4-Benzothiadiazine-7-sulfonamide, 6-chloro-, 1,1-dioxide, monosodium salt; (2) 6-Chloro-2H-1,2,4-benzothiadiazine-7-sulfonamide, 1,1-dioxide, monosodium salt. CAS-7085-44-1; CAS-58-94-6 (chlorothiazide)(1964).
Pharmacologic Category
Thiazide Diuretics. (ATC-Code: C03AA04).
Mechanism of action
Primary site of diuretic action appears to be the cortical diluting segment of the nephron. Enhances excretion of sodium, chloride, and water by interfering with the transport of sodium ions across the renal tubular epithelium. Enhances urinary excretion of potassium secondary to increased amount of sodium at distal tubular site of sodium-potassium exchange. Increases urinary bicarbonate excretion (although to a lesser extent than chloride excretion) but change in urinary pH is usually minimal (diuretic efficacy not affected by acid-base balance of patient). Increases calcium urinary excretion from a decrease in extracellular fluid volume, although calcium reabsorption in the nephron may be increased (also, slight or intermittent elevations in serum calcium concentration). Hypotensive activity in hypertensive patients (unknown mechanism; potential direct arteriolar dilation).
Therapeutic use
Mild-to-moderate hypertension. Edema.
Pregnancy and lactiation implications
Crosses the placenta. Hypoglycemia, thrombocytopenia, hemolytic anemia, electrolyte disturbances reported. May exhibit a tocolytic effect. Risk of decreased placental perfusion. Use only if heart disease or chronic hypertension started prior to gestation. Use not recommended during lactation.
Unlabeled use
Contraindications
Hypersensitivity to chlorothiazide, any component of the formulation, thiazides, or sulfonamide-derived drugs. Anuria.
Warnings and precautions
Hypokalemia, hypochloremic alkalosis, hyponatremia, and hypomagnesemia can occur. Hypersensitivity reactions may occur. Photosensitization may occur. Use in thiazide or sulfonamide allergy is specifically contraindicated. Use with caution in prediabetes or diabetes mellitus (change in glucose control may be seen). In certain patients, gout may be precipitated. Use with caution in hepatic impairment (avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy). Use with caution in moderate or high cholesterol concentrations (increased cholesterol and triglyceride levels reported with thiazides). Use with caution in hypokalemia. Avoid use in severe renal disease (ineffective; may precipitate azotemia). May cause systemic lupus erythematosus exacerbation or activation. May cause increased creatine phosphokinase, ammonia, amylase, calcium, chloride, cholesterol, glucose, increased acid, decreased chloride, magnesium, potassium, sodium. May interfere with tests for parathyroid function.