Centrally acting antihypertensive agents: a comparison of lofexidine with clonidine.

Lofexidine, a new centrally acting antihypertensive agent, was compared in a double-blind study with clonidine in the treatment of mild (standing diastolic blood pressure 95-104 mm Hg) or moderate (105-129 mm Hg) essential hypertension. In dialy dosages of 0.2 or 0.4 mg, monotherapy with lofexidine produced significant decreases in blood pressure and heart rate that were not different from those with clonidine. Blood pressure and heart rate were not different from those with clonidine. Blood pressure control (supine and standing diastolic pressure less than 90 mm Hg) occurred in seven of eight mild hypertensives treated with lofexidine and in seven of ten treated with clonidine. In moderate hypertension, three of 11 and seven of ten, ten of the 14 responders to clonidine required dosages of 0.4 mg daily or less. The maximum dosage tested was 1.6 mg daily. Concomitant hydrochlorothiazide therapy was given to eight of the lofexidine responders and 12 of the clonidine responders. For both drugs, drowsiness and dry mouth were the chief complaints. Neither agent changed standard clinical biochemistries except for decreased potassium and increased bicarbonate concentrations due to concurrent diuretic therapy. Lofexidine to have clinical characteristics similar to those of clonidine. Each of these agents is best used in lower doses, which are frequently effective and less likely to produce symptomatic complaints.