Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention.

Triamterene is a potassium-sparing diuretic that also prevents your body from absorbing too much salt and keeps your potassium levels from getting too low.

The combination of hydrochlorothiazide and triamterene is used to treat fluid retention (edema) and high blood pressure (hypertension).

Hydrochlorothiazide and triamterene may also be used for purposes not listed in this medication guide.

You should not use this medication if you are allergic to hydrochlorothiazide or triamterene, or if you have kidney disease, urination problems, high levels of potassium in your blood, or if you are taking other diuretics similar to triamterene. Do not use potassium supplements unless your doctor has told you to.

Before using this medication, tell your doctor if you have heart or liver disease, glaucoma, diabetes, a breathing disorder, gout, lupus, kidney stones, a pancreas disorder, or an allergy to sulfa drugs or penicillin.

Drinking alcohol can further lower your blood pressure and may increase certain side effects of hydrochlorothiazide and triamterene.

Avoid a diet high in salt. Too much salt will cause your body to retain water and can make this medication less effective.

Do not use potassium supplements, salt substitutes, or low-sodium milk while you are taking hydrochlorothiazide and triamterene, unless your doctor has told you to.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.

You should not use this medication if you are allergic to hydrochlorothiazide (HCTZ, HydroDiuril, Lotensin HCT, Prinzide, Zestoretic, Ziac, and others) or triamterene (Dyrenium), or if you have:

• kidney disease or are unable to urinate;

• high potassium levels (hyperkalemia);

• if you are taking diuretics similar to triamterene, such as amiloride (Midamor, Moduretic), spironolactone (Aldactone, Aldactazide); or

• if you are taking potassium supplements (unless your doctor tells you to).

To make sure you can safely take hydrochlorothiazide and triamterene, tell your doctor if you have any of these other conditions:

• diabetes;

• heart disease;

• cirrhosis or other liver disease;

• glaucoma;

• a breathing disorder;

• gout;

• lupus;

• a history of kidney stones;

• a pancreas disorder; or

• an allergy to sulfa drugs or penicillin.

FDA pregnancy category C. It is not known whether hydrochlorothiazide and triamterene will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Hydrochlorothiazide and triamterene can pass into breast milk and may harm a nursing baby. You should not breast-feed while taking hydrochlorothiazide and triamterene.