This “water pill” (diuretic) treats high blood pressure by getting rid of extra salt and water. This increases the amount of urine you make. This medication also reduces extra fluid in the body (edema) caused by conditions such as congestive heart failure, liver disease, and kidney disease. Getting rid of extra water helps to reduce fluid in the lungs so that you can breathe easier. It also helps to decrease swelling of the arms, legs, and stomach/abdomen.
This medication may also be used to treat a condition known as “water diabetes” (diabetes insipidus) and to help prevent calcium kidney stones.
How to use chlorothiazide
Take this medication by mouth with or without food, usually once or twice daily or as directed by your doctor. It is best to avoid taking this medication within 4 hours of your bedtime to avoid having to get up to urinate. Consult your doctor or pharmacist if you have questions about your dosing schedule.
If you are taking the suspension, shake the bottle well before each dose. Measure the dose carefully using a medication spoon/cup. Do not use a household spoon.
The dosage is based on your medical condition and response to therapy. In children, the dose is also based on age and weight. The manufacturer recommends that children younger than 2 years should not take more than 375 milligrams per day. Children 2-12 years old should not take more than 1,000 milligrams per day.
Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time(s) each day or as prescribed. Do not increase your dose, skip doses, or stop taking this medication unless directed by your doctor. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick. For the treatment of high blood pressure, it may take up to several weeks before the full benefit of this drug takes effect.
Cholestyramine and colestipol can decrease the absorption of this medication by your body. If you are taking either of these drugs, separate them from chlorothiazide by at least 4 hours.
Inform your doctor if your condition does not improve or if it worsens (e.g., swelling increases, your routine blood pressure readings increase).