Angiotensin II Receptor Blockers in Patients with ACE Inhibitor–Induced Angioedema

OBJECTIVE: To determine the safety of using angiotensin II receptor blockers in patients who have experienced angioedema following treatment with angiotensin-converting enzyme (ACE) inhibitors. DATA SOURCES: Clinical literature identified through MEDLINE (January 1966–August 1999). Key search terms included angioneurotic edema, angiotensin-converting enzyme inhibitors, receptors–angiotensin, and losartan. DATA SYNTHESIS: ACE inhibitor–induced angioedema occurs with an incidence of 0.1–0.5%. Alternative therapy is necessary for patients who experience this potentially life-threatening adverse effect. Since angiotensin II receptor blockers do not increase concentrations of bradykinin, the proposed mechanism of ACE inhibitor–induced angioedema, they were presumed to be safe alternatives. Recent case reports, however, document angioedema following therapy with angiotensin II receptor blockers; 32% of the reported patients experienced a prior episode of angioedema attributed to ACE inhibitor therapy. CONCLUSIONS: Until the exact cause of both ACE inhibitor– and angiotensin II receptor blocker–induced angioedema is determined, angiotensin II receptor blockers should be used with extreme caution in patients with a prior history of angioedema.