Effects of azepexole on blood pressure, pulse rate, plasma renin activity and urinary catecholamines in normotensive subjects

Single 5 mg oral doses of azepexole were administered to 6 normotensive male volunteers. Effects on blood pressure and pulse rate were recorded with the subjects supine, erect and during exercise for 8 hours after drug ingestion. Plasma renin activity and urinary catecholamine excretion were measured before and after treatment. Blood pressure was reduced when supine, erect and during exercise. The maximum reduction in systolic and diastolic blood pressure was 20.7 mmHg and 7.9 mmHg, respectively. There was a small reduction in the pulse rate when supine, significant from 2 to 3 hours after drug ingestion. Plasma renin activity increased significantly with drug treatment. There was an insignificant trend towards a reduced urinary catecholamine excretion. Only 1 subject developed significant side-effects. The similarity of azepexole to clonidine is discussed. It is considered that azepexole warrants further study as a hypotensive drug.