Hydrochlorothiazide (HCTZ) is a diuretic (water pill) used for treating high blood pressure (hypertension) and accumulation of fluid. It works by blocking salt and fluid reabsorption in the kidneys, causing an increased amount of urine containing salt (diuresis). The mechanism of its action in lowering high blood pressure is not well understood. The combination of losartan and HCTZ reduces blood pressure better than either drug alone. Losartan increases potassium levels while HCTZ reduces potassium levels; the combination of both drugs has less effect on potassium levels. The FDA approved Hyzaar in April 1995.
PRESCRIBED FOR: Hyzaar is used to treat patients with high blood pressure and for reducing the risk of stroke in patients with high blood pressure and left ventricular hypertrophy.
SIDE EFFECTS: Common side effects of Hyzaar are:
Other important side effects that may be caused by Hyzaar include:
- persistent cough,
- severe hypotension,
- changes in electrolyte concentrations,
- impotence, and
Hyzaar may reduce kidney function in some patients and should not be used by patients who have bilateral renal artery stenosis (narrowing of both arteries going to the kidneys). Rare cases of rhabdomyolysis (muscle breakdown), hepatitis, ,reduced number of platelets, and pancreatitis have been reported.
Quick GuideLowering Blood Pressure Pictures Slideshow: Exercise Tips for Getting Started
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Use the pill identifier tool on RxList.