Abstract
The hemodynamic profile of urapidil (URP) was evaluated in patients with hypertension during weight-sustaining isometric exercise (WSIE) and compared with metoprolol (MTP) and prazosin (PRZ).
Method: Forty-two patients were divided into three groups randomly after a twoweek control period. The average dose of each drug used was 4.9±1.7 mg/day for PRZ, 118±49mg/day for URP, and 143±33mg/day for MTP. WSIE was performed for four minutes before and after eight weeks of treatment. Heart rate (HR) and blood pressure (BP) were measured before exercise and at one-minute intervals during and after exercise. The cardiac index (CI) was also determined before, during, and three and six minutes after exercise by the dye dilution method using an earpiece densitometer.
Results: Thirty-one patients completed the study, and blood pressure fell equally in all groups. In the MTP group, HR and CI decreased and systemic vascular resistance (SVR) increased significantly at rest. On the other hand, PRZ increased HR and CI slightly and decreased SVR, while there was no significant change in HR and CI in the URP group.Although the increment of SVR caused by WSIE was enhanced in the MTP and PRZ groups, it was attenuated by URP treatment. The elevation of diastolic blood pressure by WSIE was also accentuated in the MTP group, while URP sun: tressed the elevation.
Conclusion: The hemodynamic effects of URP lie between those of PRZ and MTP. These results suggest that, although pharmacologically α1-antagonistic action is ten times stronger than that of β1, from a clinical standpoint URP has both α1-and β1-antagonistic action in equal balance.
