Withdrawal syndromes and the cessation of antihypertensive therapy.

A review of the available literature concerning sudden withdrawal of antihypertensive drugs shows that withdrawal syndromes after cessation of such agents have occurred with beta-blockers, methyldopa, clonidine hydrochloride, guanabenz, and bethanidine sulfate. Most commonly, these syndromes are limited to nervousness, tachycardia, headache, and nausea 36 to 72 hours after cessation of the drug. In rare cases, serious exacerbation of myocardial ischemia (beta-blockers) or hypertension (clonidine, methyldopa) may occur in the posttreatment period. The withdrawal syndromes generally respond promptly to reinstitution of antihypertensive therapy. The infrequent occurrence of withdrawal syndromes should not discourage use of these efficacious agents.