Generic Name: hydrochlorothiazide and irbesartan (hyde droe klor oh THYE a zide and ER beh sar tan) Brand Names: Avalide What is the most important information I should know about hydrochlorothiazide and irbesartan? • Do not take hydrochlorothiazide and irbesartan if you are pregnant or planning a pregnancy. When used during the second and third trimesters of pregnancy, irbesartan can cause injury and even death to the developing baby. Notify your doctor immediately if you think you might be pregnant. • Use caution when driving, operating machinery, or performing other hazardous activities. Hydrochlorothiazide and irbesartan may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. Also use caution when rising from a sitting or lying position. • Stop taking hydrochlorothiazide and irbesartan and contact your doctor if lightheadedness or fainting occurs. • Use alcohol cautiously. Alcohol may increase the drowsiness and dizziness that may occur while you are taking an hydrochlorothiazide and irbesartan. • Avoid prolonged exposure to sunlight. Hydrochlorothiazide and irbesartan may increase the sensitivity of your skin to sunlight. Use a sunscreen and wear protective clothing when exposure to the sun is unavoidable. What are hydrochlorothiazide and irbesartan? • Irbesartan is an angiotensin II receptor inhibitor, also called angiotensin II receptor antagonist, and is used to treat hypertension (high blood pressure). • Hydrochlorothiazide is a thiazide diuretic (water pill). It increases the amount of water and salt you lose in your urine and decreases edema (swelling or fluid retention). • Together, hydrochlorothiazide and irbesartan are used to reduce hypertension (high blood pressure). • Hydrochlorothiazide and irbesartan may also be used for purposes other than those listed in this medication guide.