Which antihypertensive can cause lip swelling and angioedema?

• A. Lisinopril
• B. Amlodipine
• C. Hydrochlorothiazide
• D. Losartan

Answer: (A)

Lisinopril is an ACE inhibitor, and a key adverse effect of ACE inhibitors is angioedema, especially swelling of the lips, face, or tongue. This happens because blocking ACE prevents the breakdown of bradykinin, a peptide that promotes vasodilation and increases vascular permeability. When bradykinin levels rise, tissues in the lips and airway can swell, which can be life-threatening if the airway is affected.

Understanding this helps differentiate it from other antihypertensives. For example, calcium channel blockers like amlodipine can cause swelling, but typically as peripheral edema in the legs due to arteriolar dilation and fluid shifts, not lip angioedema. Diuretics like hydrochlorothiazide don’t cause this bradykinin-mediated swelling. Angiotensin receptor blockers (losartan) are less likely to cause angioedema because they don’t increase bradykinin as ACE inhibitors do, though rare cases can still occur.

Therefore, the antihypertensive associated with lip swelling and angioedema in this context is the ACE inhibitor. If this occurs, the ACE inhibitor should be stopped and airway safety prioritized; an alternative antihypertensive such as an ARB may be considered with caution if appropriate.