Labetalol in the treatment of hypertensive renal patients.

The efficacy of labetalol in lowering blood pressure was assessed in 18 patients with chronic renal failure and hypertension. Before the start of labetalol therapy, all patients were receiving combined antihypertensive therapy, the most common being a beta-blocker and hydrallazine. Over the period of about four weeks labetalol was substituted for the prior therapy. 51Cr edetic acid (EDTA) estimations of glomerular filtration rate were performed before labetalol therapy, and then again after one and six months. Before the therapy with labetalol, 12 of the 18 patients had supine diastolic blood pressures of 100 mm Hg or more. At six months, 14 patients remained in the trial and, of these, only four had a supine diastolic blood pressure of 100 mm Hg or more. In the supine position there was a significant reduction of systolic, but not of diastolic, blood pressure. However, in the erect position there was a significant reduction both in systolic and in diastolic blood presure. Pulse rate did not vary significantly. Few side effects were encountered, transient postural dizziness being the most common side effect. Labetalol seems to be an effective substitute for the beta-blocker plus hydrallazine therapy. However, it is not as potent as minoxidil.