Renal effects of 4-week fixed maintenance doses of
bunazosin three times daily (2.0 mg t.i.d., n = 8) and
propranolol (40 mg t.i.d., n = 8) were evaluated in patients with mild-to-moderate
essential hypertension [World Health Organization (WHO) stages I and II]. Both
bunazosin and
propranolol decreased blood pressure (BP) significantly (p less than 0.05), but the magnitude of reduction in diastolic BP (DBP) was greater with
bunazosin (p less than 0.05) than with
propranolol.
Bunazosin produced a nonsignificant increase in renal blood flow (RBF) by 14%, a significant increase in glomerular filtration rate (GFR) 11% (p less than 0.05), and a decrease in total renal vascular resistance (TRR) by 15% (p less than 0.05), whereas
propranolol caused no significant changes in these parameters. Urinary
sodium excretion rate and the fractional excretion of
sodium were unchanged by either of the drugs. The results of this short-term study suggest that
bunazosin may be a
drug that will increase RBF and GFR and decrease TRR with a concomitant hypotensive action in patients with mild-to-moderate
essential hypertension. Whether these renal functional effects of the
drug would benefit such patients must be determined in long-term studies.