Abrupt discontinuation of clonidine therapy.

Clonidine therapy was discontinued abruptly in seven patients. Blood pressure was recorded every hour or two hours throughout the study. Clonidine therapy was reinstituted 48 hours after its discontinuation in all except two patients, in whom it was reinstituted at 36 hours. During the withdrawal phase, blood pressure tended to return rapidly to nontreatment levels, but there was no "overshoot" in blood pressure. Apprehension, insomnia, palpitations, and sweating were experienced by two patients. These symptoms were relieved promptly by reinstituting clonidine therapy. In this prospective study, no blood pressure overshoot was noted with abrupt discontinuation of clonidine.