Clonidine-chlorthalidone combination once and twice daily in essential hypertension

The antihypertensive effects of a clonidine-chlorthalidone combination (Combipres) as a single daily dose at bedtime and the same amount in twice-daily doses were compared in an open-label, crossover study in 14 patients. An analysis of the blood pressure and pulse data in nine patients who completed the study revealed no statistically significant differences between the two regimens, and no difference in the incidence of side effects was noted.