A comparative trial of clonidine, propranolol and placebo in the treatment of moderate hypertension.

1 A double-blind cross over trial between clonidine, propranolol and a placebo in patients with moderate hypertension has been performed. 2 Thirty-two patients completed the study which consisted of three treatment periods in random order of 3 months each. Patients had their blood pressure recorded by an unbiased observer using a random-zero machine. 3 Both clonidine and propranolol produced a significant reduction in blood pressure (P less than 0.01), which was apparent by the second week of therapy. Propranolol gave a greater reduction in pulse rate than clonidine (P less than 0.01) but clonidine also reduced the pulse rate significantly (P less than 0.05). There was no evidence of postural hypotension on either drug. Side-effects were more common with clonidine but these tended to wear off after several weeks of therapy. 4 Clonidine and propranolol were equipotent in reducing blood pressure, but clonidine has more initial side-effects than propranolol.