By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Avalide is a combination of irbesartan (Avapro) and hydrochlorothiazide. Irbesartan is one of the angiotensin receptor blockers, the others avalaible in the US being losartan (Cozaar), valsartan (Diovan), telmisartan (Micardis), candesartan (Atacand), and eprosartan (Teveten). These drugs work by blocking the effects of angiotensin, which constricts blood vessels and promotes the secretion of a salt-retaining hormone called aldosterone; both of these effects will tend to raise the blood pressure. The end result is similar to the effects of angiotensin converting enzyme (ACE) inhibitors, but unlike ACE inhibitors, the angiotensin receptor blockers don’t cause cough as a side effect. The angiotensin receptor blockers are more effective when given in combination with a diuretic, and several of them are marketed as combination drugs, such as Hyzaar (losartan plus hydrochlorothiazide) and Diovan.HCT (valsartan plus hydrochlorothiazide).

Although the angiotensin receptor blockers all work in the same way, there are differences in their relative potency. Two of the drugs, irbesartan and candesartan, produce more profound blockade of angiotensin than the others, and have been found to produce a greater reduction of blood pressure than losartan.

The side effects of Avalide are infrequent, and include fatigue, nausea, and dizziness. It should not be taken during pregnancy.

Avalide is available in two strengths: 150 mgs of irbesartan with 12.5 mgs of hydrochlorothiazide, and 300 mgs of irbesartan with 12.5 mgs of hydrochlorothiazide. The usual starting dose is 150 mg, given once a day.