Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from
absorbing too much salt, which can cause fluid retention.
Irbesartan is in a group of drugs called angiotensin II receptor antagonists. Irbesartan keeps
blood vessels from narrowing, which lowers blood pressure and improves blood flow.
The combination of hydrochlorothiazide and irbesartan is used to treat high blood pressure
(hypertension).
Hydrochlorothiazide and irbesartan may also be used for other purposes not listed in this
medication guide.