ACE inhibitor
ACE inhibitors can induce angioedema. ACE inhibitors block the enzyme ACE so it can no longer degrade bradykinin; thus, bradykinin accumulates and can cause angioedema. This complication appears more common in African-Americans. In people with ACE inhibitor angioedema, the drug needs to be discontinued and an alternative treatment needs to be found, such as an angiotensin II receptor blocker (ARB), which has a similar mechanism but does not affect bradykinin. However, this is controversial, as small studies have shown some patients with ACE inhibitor angioedema can develop it with ARBs, as well.