Angioedema due to losartan

To report a case of angioedema associated with the angiotensin II receptor antagonist losartan.

A 62-year-old African-American woman was admitted to the hospital for acute renal failure and uncontrolled hypertension. After attempting blood pressure control with three different agents, captopril was combined with metoprolol. The patient noted swelling of the lips combined with shortness of breath after four days of captopril. Losartan was substituted for captopril, which then produced similar swelling of the lips (without shortness of breath) after only one dose. These symptoms resolved after discontinuation of losartan and administration of antihistamines.

Losartan, like other angiotensin II receptor antagonists, blocks the action of angiotensin II at the receptor level. Five published case reports involved patients with a prior history of intolerance to the angiotensin-converting enzyme inhibitors. Two published case reports of similar reactions also occurred in patients with renal compromise. The mechanism for this reaction from losartan is not known, but may not be due to bradykinin excess.

Clinicians should be aware that angiotensin receptor antagonists may not be safe alternatives in patients who have a history of angioedema secondary to the angiotensin-converting enzyme inhibitors.