Effect of Pindolol on Blood Pressure, Plasma Renin Activity, and Catecholamines in Hypertensive Patients

Abstract

The effects of 45 mg pindolol daily on blood pressure, heart rate, plasma renin activity, and plasma catecholamines were assessed on 11 hospitalized hypertensive patients. Blood pressure decreased significantly after nine days of treatment, but heart rate remained unchanged. Plasma renin activity was in the same average range before and during treatment, with individual values variably increasing, decreasing, or remaining unchanged. Blood pressure changes were independent from the baseline level of plasma renin activity or the change in renin activity observed during treatment. Plasma epinephrine and norepinephrine levels also remained unchanged during treatment. Lack of change in heart rate and hormonal levels may be attributed to the combined effects of the β‐antagonistic and partial agonistic properties of this agent. Thus, pindolol used as monotherapy at this dose significantly lowered blood pressure, but not to normal levels, with only minimal side effects. Because of its combined adrenergic agonistic and antagonistic effects, it may be a preferable alternative to pure antagonists in selected patients.

How intrinsic sympathomimetic activity modulates the haemodynamic responses to beta‐adrenoceptor antagonists. A clue to the nature of their antihypertensive mechanism.

“…Accordingly the rise in plasma noradrenaline in no way excludes an effect of prejunctional Padrenoceptor blockade. Furthermore, it has been shown that during treatment with pindolol plasma noradrenaline does decrease (Walter et al, 1973;Anavekar et al, 1975;Brecht et al, 1976aBrecht et al, , 1976bLang et al, 1978;Winer et al, 1978;Franz et al, 1980, Gavras et al, 1981Kirsten et al, 1982;Wilcox et al, 1981), (Table 2). It has also been shown that in the course of treatment with practolol, the urinary excretion of catecholamines is reduced by 65 % (Esler & Nestel, 1973).…”