Chlorothiazide
Chlorothiazide is a thiazide diuretic used to treat high blood pressure and fluid retention (edema) by helping the kidneys remove excess salt and water from the body. It is commonly prescribed for hypertension, heart failure, and certain kidney disorders. This medication is typically used when diet and lifestyle changes alone are insufficient to control blood pressure.
Chlorothiazide is a thiazide diuretic that lowers blood pressure and reduces fluid retention by increasing urine output.
Key facts at a glance
- ATC
- C03AA04
- RxNorm
- 2396
- Generic
- Chlorothiazide
- Class
- atc-c03
- Brands
- Diuril
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- oral
- Forms
- tablet, suspension, injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Chlorothiazide is used to treat hypertension (high blood pressure), heart failure-related edema, liver cirrhosis-associated fluid accumulation, and nephrotic syndrome. It may also be used as adjunctive therapy in certain cases of diabetes insipidus.
Chlorothiazide inhibits sodium reabsorption in the distal convoluted tubules of the kidney, promoting the excretion of sodium, chloride, and water. This reduces plasma volume and cardiac output, leading to decreased blood pressure. The increased sodium delivery to the collecting duct enhances potassium excretion, which is an important consideration during therapy.
Common side effects include electrolyte imbalances (low potassium, sodium, and magnesium), increased urination, dizziness, and elevated blood sugar. Patients should have their electrolytes and kidney function monitored regularly. Thiazides may increase uric acid levels and should be used cautiously in patients with gout. The medication may cause photosensitivity, and patients should use sun protection. Alcohol and other blood pressure medications may enhance the hypotensive effect.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy