Hydrochlorothiazide

Why is this medication prescribed?

Hydrochlorothiazide, a 'water pill,' is used to treat high blood pressure and fluid retention caused by various conditions, including heart disease. It causes the kidneys to get rid of unneeded water and salt from the body into the urine.

This medicine is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Hydrochlorothiazide comes as a tablet and liquid to take by mouth. It usually is taken once or twice a day. If you are to take it once a day, take it in the morning; if you are to take it twice a day, take it in the morning and in the late afternoon to avoid going to the bathroom during the night. Take this medication with meals or a snack. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take hydrochlorothiazide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Hydrochlorothiazide controls high blood pressure but does not cure it. Continue to take hydrochlorothiazide even if you feel well. Do not stop taking hydrochlorothiazide without talking to your doctor.

Other uses for this medicine

Hydrochlorothiazide may also be used to treat patients with diabetes insipidus and certain electrolyte disturbances and to prevent kidney stones in patients with high levels of calcium in their blood. Talk to your doctor about the possible risks of using this medicine for your condition.

What special precautions should I follow?

Before taking hydrochlorothiazide,

• tell your doctor and pharmacist if you are allergic to hydrochlorothiazide, sulfa drugs, or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially other medicines for high blood pressure, anti-inflammatory medications such as ibuprofen (Motrin, Nuprin) or naproxen (Aleve), corticosteroids (e.g., prednisone), lithium (Eskalith, Lithobid), medications for diabetes, probenecid (Benemid), and vitamins. If you also are taking cholestyramine or colestipol, take it at least 1 hour after hydrochlorothiazide.
• tell your doctor if you have or have ever had diabetes, gout, or kidney, liver, thyroid, or parathyroid disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking hydrochlorothiazide, call your doctor immediately.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking hydrochlorothiazide.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
• remember that alcohol can add to the drowsiness caused by this drug.
• plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Hydrochlorothiazide may make your skin sensitive to sunlight.

What special dietary instructions should I follow?

Follow your doctor's directions. They may include following a daily exercise program or a low-salt or low-sodium diet, potassium supplements, and increased amounts of potassium-rich foods (e.g., bananas, prunes, raisins, and orange juice) in your diet.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Frequent urination should go away after you take hydrochlorothiazide for a few weeks. Tell your doctor if any of these symptoms are severe or do not go away:

• muscle weakness
• dizziness
• cramps
• thirst
• stomach pain
• upset stomach
• vomiting
• diarrhea
• loss of appetite
• headache
• hair loss

If you experience any of the following symptoms, call your doctor immediately:

• sore throat with fever
• unusual bleeding or bruising
• severe skin rash with peeling skin
• difficulty breathing or swallowing