Comparative efficacy and safety of lofexidine and clonidine in mild to moderately severe systemic hypertension.

The comparative efficacy and safety of lofexidine and clonidine in patients with mild to moderate systemic hypertension were evaluated. Patients who met established criteria were administered lofexidine or clonidine in a double-blind manner. The dose of either drug, along with hydrochlorothiazide if necessary, was titrated to blood pressure response or to the occurrence of side effects. Treatment with the dose established during titration was continued for 12 weeks. Blood pressure and the occurrence of side effects were evaluated during weekly clinic visits. Twenty-six patients completed all portions of the study. The decrease in blood pressure compared with that with the placebo was significant for both drugs (p less than 0.05). The daily dose of clonidine required for blood pressure control was less than that of lofexidine (p less than 0.05). Concomitant diuretic therapy was required equally as often for both drugs. Clonidine caused adverse effects more frequently than did lofexidine. The effectiveness of lofexidine is comparable to that of clonidine, but lofexidine has a lower incidence of toxicity.