Angiotensin II receptor blocker-associated angioedema: on the heels of ACE inhibitor angioedema.

Angioedema and cough are known side effects of angiotensin-converting enzyme (ACE) inhibitors. Angiotensin-converting enzyme is a potent inhibitor of kinase II, which facilitates the breakdown of bradykinin. An increase in bradykinin levels results in continued prostaglandin E2 synthesis, vasodilation, increased vascular permeability, and increased interstitial fluid. In contrast, the angiotensin II receptor blockers (ARBs) do not increase bradykinin levels. Angioedema as a complication of ACE inhibitor therapy is not widely recognized; this complication is even less recognized with second-line ARBs. We report angioedema associated with losartan (an ARB) in a patient who had experienced angioedema secondary to enalapril (an ACE inhibitor). Almost half of patients with ARB-associated angioedema also had developed angioedema while receiving ACE inhibitor therapy. Clinicians should exercise caution when using ARBs in patients with a history of angioedema secondary to ACE inhibitors.