[Antihypertensive therapy with a new beta-blocking agent Timolol. Double blind study and comparison with Alprenolol and Pindolol (author's transl)].

In a double blind study including 24 patients with essential hypertension the beta-blocking agent Timolol showed a mild antihypertensive effect. These patients had been pretreated with hydrochlorothiazid to which they responded already with a significant lowering of their blood pressure before Timolol was added. The effect of Timolol equals the effects of Pindolol and Alprenolol. We also found a suppression of the plasma-renin-activity under Timolol. This effect did not correlate with the degree of blood pressure reduction. There were no side effects noted except for a lowering of the pulse rate about which some of the patients complained and which is typical for beta blocking agents without intrinsic symphaticomimetic activity. According to our results this new beta blocking agent for antihypertensive therapy has very much the same properties as the other beta-blocking drugs already in use.