Effect of Bevantolol Hydrochloride, a β-Blocker, on Hemodynamics in the Resting State and during Exercise Loading in Essential Hypertensives

Bevantolol hydrochloride is a new β1-selective β-adrenoceptor antagonist without intrinsic sympathomimetic activity. It has been also reported that bevantolol has α1-blocking activity and calcium antagonistic action. The effects of bevantolol on hemodynamics in the resting state and during exercise loading were investigated in 7 patients with mild or moderate essential hypertension.The treatment of bevantolol was started from 100mg twice a day. If an adequate antihypertensive effect was not obtained after 4 or more weeks of treatment, the dose of bevantolol was increased to 200mg twice a day. Before and after treatment for 16-26wk by bevantolol, the hemodynamics were measured in resting state and during exercise loading using a bicycle ergometer with the constant load of 1.25W/kg for 6min. Blood pressure, heart rate and cardiac output were measured and total peripheral resistance was calculated. In addition, plasma renin activity and concentration of aldosterone, norepinephrine and epinephrine in plasma were measured. One patient was excepted from the analysis because of lacking the measurement after the treatment. In the results, (1) bevantolol reduced blood pressure and heart rate in resting state. Cardiac output was invariable, and total peripheral resistance decreased after the treatment. (2) Bevantolol reduced the increase of blood pressure, heart rate and cardiac output during exercise loading. No significant change was found in the total peripheral resistance during exercise loading. (3) Plasma renin activity decreased after the treatment period. No changes were found in the plasma concentration of aldosterone, norepinephrine and epinephrine.Based on the above, bevantolol is considered to reduce blood pressure without being accompanied by increase of total peripheral resistance. It is supposed that the result is caused by not only β1-selective β-blocking action of bevantolol, but also the participation of its α1-blocking action and calcium antagonistic action.From these results, it is concluded that bevantolol, in spite of β-blockers, is useful in treating patients in hypertension without increase of total peripheral resistance in resting state and during exercise loading.