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Zorluk: KolayImmunologic and Inflammatory Processes

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?

  1. LisinoprilCevap
  2. B
    Losartan
  3. C
    Metoprolol
  4. D
    Amlodipine
  5. E
    Hydrochlorothiazide

Cevap

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.

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1
Identify the patient's underlying condition.
The patient has hereditary angioedema (HAE), indicated by recurrent non-pruritic swelling, family history, and confirmed C1 esterase inhibitor deficiency.
Establishing the correct diagnosis is required to understand which pharmacologic pathways are disrupted.
2
Determine the pathophysiologic mechanism of the disease.
C1 esterase inhibitor deficiency leads to unchecked kallikrein activity and subsequent overproduction of bradykinin, which causes the severe tissue swelling.
Understanding the bradykinin excess explains the patient's baseline risk for angioedema.
3
Evaluate the medication options for contraindications related to bradykinin.
Lisinopril (an ACE inhibitor) blocks the degradation of bradykinin. It is strictly contraindicated as it can precipitate life-threatening swelling.
ACE inhibitors are a well-known trigger for angioedema and must be avoided in patients who already have a genetic predisposition to elevated bradykinin.

Anahtar Kavram

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.
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