Prizidilol in essential hypertension: long-term effects on plasma volume, extracellular fluid volume, and central...

We studied the long-term hemodynamic effect of prizidilol (a precapillary vasodilator and beta-adrenoceptor blocker) in 14 men aged 25-66 years with mild and moderate essential hypertension (EH). Cardiac output (by Cardiogreen) and intraarterial blood pressure (BP) were measured at rest and during exercise before and after 8 months of therapy. Changes in body fluid volumes were measured by isotope dilution techniques. After 8 months on prizidilol, eight of the 14 patients were normotensive, and the mean casual BP was lowered by 23/17 mm Hg to 140/91 mm Hg. The intraarterial systolic and diastolic pressures fell by 15-20% of the pretreatment levels at rest supine, sitting, and during 50, 100 and 150 W exercise. The fall in BP was due to a marked reduction in total peripheral resistance ranging from 17 to 23% at rest and during exercise. Cardiac output was unchanged at all work loads, whereas heart rate fell. The stroke volume increased in all settings; at maximum work load by 30%. Body weight and body fluid volumes did not change significantly. Except for some coldness in hands and feet in one patient, which disappeared after 2-3 months, no side effects were observed. We conclude that, in mild and moderate EH, prizidilol induces a substantial fall in BP with an excellent hemodynamic profile both at rest and during exercise.