Effect of practolol on blood pressure and renin release in man.

Abstract

The effect of the β‐adrenergic receptor‐blocking drug, practolol, on plasma renin activity at rest and on the renin response to a graded isoproterenol (isoprenaline) infusion has been studied in man. Plasma renin activity at rest was not significantly changed by parenteral practolol. With isoproterenol, a dose of practolol that produced 50% to 60% reduction in the heart rate response to isoproterenol was without effect on the renin response. With chronic oral dosage of practolol, in 11 patients with essential hypertension, there was no significant change in plasma renin activity. The fall in blood pressure in these patients was unrelated to the pretreatment plasma renin level. Practolol, a “cardioselective” β‐adrenergic blocking drug, appears to lower blood pressure by a mechanism unrelated to inhibition of renin release.