Do not use this medication if you are allergic to hydrochlorothiazide or valsartan, or if you are unable to urinate.
Do not use this medication without telling your doctor if you are pregnant. Valsartan may cause injury and even death to the unborn baby if you take it during the second and third trimesters of pregnancy. Use an effective form of birth control. Stop using this medication and tell your doctor right away if you become pregnant during treatment.
Before using hydrochlorothiazide and valsartan, tell your doctor if you have congestive heart failure, kidney or liver disease, asthma, low or high blood levels of potassium, gout, lupus, diabetes, or an allergy to sulfa drugs.
Avoid drinking alcohol. It can lower your blood pressure and may increase some of the side effects of hydrochlorothiazide and valsartan.
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.
Do not use potassium supplements or salt substitutes while you are taking hydrochlorothiazide and valsartan, unless your doctor has told you to.
In rare cases, hydrochlorothiazide and valsartan can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. Call your doctor right away if you have muscle pain, tenderness, or weakness especially if you also have fever, nausea or vomiting, and dark colored urine.