Double‐blind Comparison of Two Beta‐blocking Drugs With Previous Therapy in the Treatment of Hypertension

A double-blind controlled study has been carried out to compare the effects of prindolol and propranolol in the treatment of hypertension. These beta-blocking drugs were compared with one another and with previous therapy and allocation was by the random envelope method. Previous therapy was gradually replaced with units of identical capsules containing prindolol or propranolol, and after a period of three months, the patients crossed over to a treatment with the other beta-blocking agents. The mean supine, systolic and diastolic blood pressure levels were significantly lower during treatment with prindolol or propranolol than they had been on the previous therapy. The postural fall which occurred on standing was significantly less during treatment with beta-blocking agents than during treatment with a variety of other hypotensive agents. There were no significant differences between prindolol and propranolol. The side effects which were recorded regularly on questionnaires were considerably less during treatment with beta-blocking agents. The results of this study show that in moderate and severe hypertension a combination of a thiazide diuretic and prindolol or propranolol achieves satisfactory blood pressure control. This combination also allows better control of supine blood pressure levels, less postural hypotension, and less side effects than were recorded during treatment with other hypotensive agents.