Acute rebound hypertensive episodes have been reported to occur with the sudden withdrawal of which medication?

• A. Verapamil
• B. Lisinopril
• C. Clonidine
• D. Furosemide

Answer: (C)

Sudden stopping of a drug that suppresses central sympathetic outflow can trigger rebound hypertension. Clonidine is an alpha-2 adrenergic agonist that lowers blood pressure by decreasing central sympathetic tone. When it is withdrawn abruptly, the brake on sympathetic activity is released, leading to a surge of norepinephrine, rapid vasoconstriction, and a sharp rise in blood pressure (often with tachycardia, headaches, and anxiety). This rebound hypertensive response is classic for clonidine withdrawal.

Verapamil, lisinopril, and furosemide do not produce this abrupt, pronounced rebound hypertension upon sudden cessation. Verapamil withdrawal mainly risks return of baseline rhythm and blood pressure; lisinopril withdrawal tends to revert to pretreatment levels without a distinct hypertensive crisis; furosemide withdrawal can cause fluid shifts but not a targeted rebound of hypertension.