Withdrawal Syndrome Following Cessation of Guanabenz Therapy

Abstract

A withdrawal syndrome consisting of nervousness, palpitations, diaphoresis, and insomnia appeared in 3 patients within 16-48 h following discontinuation of guanabenz, a new centrally acting antihypertensive agent. A similar syndrome of sympathetic overactivity has been described with abrupt withdrawal of clonidine. Three of 4 patients treated with 48 mg/day but none of 20 other patients treated with 32 mg/day or less guanabenz developed this syndrome. None of the 3 patients developed hypertensive crisis, though 1 had a modest rise in the blood pressure above baseline levels. Guanabenz therapy apparently should not be discontinued abruptly and, when possible, the dosage should be limited to less than 48 mg/day.