Return of elevated blood pressure after withdrawal of antihypertensive drugs.

Abstract

The rate at which arterial pressure rises after discontinuing active treatment was investigated in a group of 86 hypertensive patients who received treatment with hydrochlorothiazide, reserpine and hydralazine for two years or longer and whose diastolic pressures averaged below 96 mm Hg for the last year of treatment. Sixty patients were assigned double-blind to placebos and 26 were continued on active drugs. Forty-two of the placebo group of patients were removed over an 18 month follow-up because of return of elevated blood pressures, 39 being removed in the first six months. Six patients in the placebo group and none in the treated group were removed because of morbid events. Nine or 15% of the placebo patients remained normotensive. The rate of rise in arterial pressure in the placebo group appeared to be related directly to the height of the pressure prior to initiation of active treatment and inversely to the age of the patients. Serum uric acid fell significantly while serum potassium rose significantly after active treatment was discontinued. The glucose tolerance test changed slightly in a direction toward normal while serum creatinine showed no significant change.