[Comparative effects on renal function of 4 beta-blockers injected intravenously].

Four beta-blockers: atenolol 15 mg i.v., metoprolol 25 mg i.v., acebutolol 45 mg i.v. and labetalol 50 mg i.v. were administered to 106 patients suffering from hypertension and with normal or disturbed renal function. During an identical test protocol, measurements of clearance of inulin, of PAH, urine sodium and the fraction of sodium excreted were recorded one hour before and four or five hours after administration of the antihypertensive. Mean blood pressure and heart rate were also recorded. The three pure beta-blockers reduced inulin and PAH clearance and lowered urine sodium. These modifications were the same for all three drugs. Labetalol, which also possesses alpha-blocking properties, did not reduce renal function values or urine sodium. While a slight fall in blood pressure occurred with all the antihypertensives, heart rate was reduced only by the three pure beta-blockers. The action of the four drugs was very similar whatever the state of the subject's renal function. The study of the renal effects of the beta 1-selective atenolol and metoprolol, and acebutolol which has a higher intrinsic sympathomimetic activity does not demonstrate any significantly different renal action among these three drugs, but the effects of labetalol on renal function values and urine sodium are slighter. The renal action of the beta-blockers cannot be fully explained. Though the fall in the renal plasma flow and in the glomerular filtration rate can be related partly to the decrease in the cardiac output consequent to induced bradycardia, stimulation of renal alpha-receptors must be considered.(ABSTRACT TRUNCATED AT 250 WORDS)