新しいβ１選択性β遮断薬塩酸ｂｅｖａｎｔｏｌｏｌの日本人健常成人における薬物動態と薬理作用

Abstract

Clinicopharmacological study of bevantolol, a newly developed β1-selective β-blockingagent was carried out in Japanese healthy male volunteers. The pharmacokinetics, pharmacodynamics, and safety were investigated after single and once-daily repeated oraladministration of 100 mg and 200 mg of bevantolol. The following results were obtained.(1) The time to the maximum plasma concentration (tmax) on an empty stomach was about 0.7 hr and the elimination half-life in α-phase (t1/2α) and in β-phase (t1/2β) were about 1. 4 hr and 9 to 10 hr, respectively. The area under the plasma concentration curve (AUC) and the maximum plasma concentration (Cmax), which showed about a threefold interindividual variation, were about two times greater after the 200 mg dose than after the100 mg dose.(2) On a full stomach, tmax was prolonged to 2 hr. No sign of accumulation was noted after seven days of once-daily repeated doses.(3) The reduction in resting blood pressure after dosing of bevantolol was mild, while pulse rate decreased singnificantly. Fall in blood pressure after postural change from supine to standing position was not evident.(4) Exercise-induced tachycardia and increase in rate-pressure product were significantly attenuated by bevantolol. A high correlation existed between the percent reduction [%R] HR in exercise-induced tachycardia and the logarithm of the plasma concentration of bevantolol.(5) Resting fingertip blood flow measured by venous occlusion plethysmography did not decrease after repeated doses of 100 mg of bevantolol.(6) Regarding subjective symptoms, complaints of headache, dull headache, and gastrointestinal disturbance were noted in some subjects. No profound influence was recognized on the clinical laboratory data. After repeated doses of 100 mg of bevantolol, one subject developed transient loss of consciousness accompanied by a fall in blood pressure and pulse rate. Therefore, careful attention should be paid when the drug isused.