The phase 1 study of bucumolol, a new β-blocking agent was carried out to examine its pharmacological actions and safety in normal volunteer subjects. A single dose of 10 mg was orally administered as a suitable dose on the basis of the experimental results obstained in animals, and compared with 20 mg propranolol in the double blind manner.
The heart rate significantly decreased both at rest and during exercise on the use of each drug by almost equal extent. However, blood pressure lowering action was scarecely observed by bucumolol. The PEP and PEP/LVET in systolic time intervals were prolonged following administration of bucumolol in the supine position, indicating the presence of negative inotropic effect.
The administration was continued for 2 weeks, but no significant changes were noted in the subjective symptoms, hematological data and cardiothoracic ratio in chest X-ray films. From these results, it was confirmed that bucumolol of 10 mg has an effect to decrease heart rate and exerts a negative inotropic action without untoward actions.
