Once daily dosage beta-blockade: antihypertensive efficacy of slow release oxprenolol as related to renin and age.

A single daily dose antihypertensive therapy with a new slow-release (SR) form of the beta-adrenoceptor blocking agent oxprenolol was as effective as a standard tid beta-blocker regimen in maintaining therapeutic effects over 24 hours. The good overall response rate (target larger than or equal to mmHg diastolic) of 67% was achieved in eight of the 11 high renin patients and 16 out of the 20 normal renin ones; the five low renin patients, who were also older, proved to be non-responsive. In terms of age, 83% of the patients aged under 40 years showed a reduction in diastolic pressure to larger than or equal to 95 mmHg, this percentage being significantly better than the 50% response rate in the 40--56-year-olds. In nine of the 12 beta-blocker non-responders the diastolic blood pressure was reduced to larger than 95 mmHg by adding a diuretic, and in four of the nine, all of them low renin patients, this effect persisted in response to diuretics alone. Oxprenolol SR suppresses renin acutely (59%) and chronically (62%), and it blunts the renin stimulatory effects of diuretics.