Avapro (irbesartan) is an angiotensin II receptor antagonist that acts by inhibiting negative feedback of angiotensin II on renin secretion, but the resulting increase in plasma renin activity does not compromise the effects that irbesartan has on blood pressure. This antihypertensive is often used in combination with other blood pressure reducing agents, and unlike ACE inhibitors, irbesartan does not the coughing side effect that is so common with these agents. Side effects include chills, fever, facial edema, sleeplessness, and some slight visual disturbance.