A 32-year-old man visits the primary care clinic to establish care and discuss management of recently diagnosed essential hypertension. He reports a lifelong history of episodic, unprovoked swelling of his lips, tongue, and extremities. These episodes typically last 48 to 72 hours and are not associated with urticaria or pruritus. His father and paternal grandfather experienced similar symptoms throughout their lives. Recent laboratory testing confirms a deficiency of C1 esterase inhibitor. The patient's blood pressure today is 152/94 mm Hg. The physician decides to initiate antihypertensive therapy. Which of the following medications is strictly contraindicated in this patient?
- LisinoprilAnswer
- BLosartan
- CMetoprolol
- DAmlodipine
- EHydrochlorothiazide
Answer
Lisinopril
The correct medication to avoid is an angiotensin-converting enzyme (ACE) inhibitor, such as lisinopril. ACE is also known as kininase II, the enzyme largely responsible for degrading bradykinin. This patient has hereditary angioedema due to C1 esterase inhibitor deficiency, a condition characterized by excessive bradykinin production. Administering an ACE inhibitor to this patient prevents the breakdown of bradykinin, leading to massive accumulation that can rapidly precipitate severe, life-threatening airway edema.
Step-by-Step Solution
Key Concept
Patients with hereditary angioedema (C1 esterase inhibitor deficiency) have elevated bradykinin levels. Angiotensin-converting enzyme (ACE) inhibitors prevent the degradation of bradykinin and are strictly contraindicated as they can precipitate severe, potentially fatal angioedema.