Which medication is most likely to cause angioedema in an elderly patient presenting with new facial swelling?

Which medication is most likely to cause angioedema in an elderly patient presenting with new facial swelling?

• A. Aspirin
• B. Fosinopril
• C. Penicillin
• D. Metformin

Answer: (B)

Angioedema from medications is often caused by agents that affect bradykinin metabolism. Fosinopril is an ACE inhibitor, and ACE normally helps break down bradykinin. When ACE is blocked, bradykinin accumulates, leading to dilation of blood vessels and increased vascular permeability. This produces non-itchy, non-urticarial swelling of the face, lips, and sometimes the tongue or airway—classic features of ACE inhibitor–induced angioedema. In an elderly patient with new facial swelling, this mechanism points strongly to a drug like fosinopril as the likely cause. The reaction can occur at any time after starting therapy and can be life-threatening if the airway is compromised, so stopping the ACE inhibitor is essential and urgent evaluation of the airway is warranted. Aspirin and penicillin can cause allergic angioedema through histamine-mediated pathways with itching or hives, and metformin is not a typical cause of angioedema.

Angioedema from medications is often caused by agents that affect bradykinin metabolism. Fosinopril is an ACE inhibitor, and ACE normally helps break down bradykinin. When ACE is blocked, bradykinin accumulates, leading to dilation of blood vessels and increased vascular permeability. This produces non-itchy, non-urticarial swelling of the face, lips, and sometimes the tongue or airway—classic features of ACE inhibitor–induced angioedema. In an elderly patient with new facial swelling, this mechanism points strongly to a drug like fosinopril as the likely cause. The reaction can occur at any time after starting therapy and can be life-threatening if the airway is compromised, so stopping the ACE inhibitor is essential and urgent evaluation of the airway is warranted.

Aspirin and penicillin can cause allergic angioedema through histamine-mediated pathways with itching or hives, and metformin is not a typical cause of angioedema.