General and cerebral haemodynamic activity of ethyl apovincaminate.

Systemic and cerebral haemodynamic effects of ethyl apovincaminate (RGH-4405, Cavinton), a new compound, have been investigated in anaesthetized dogs. The compound was administered i.v. and produced an increase in cerebral blood flow accompanied by a decrease in cerebral vascular resistance which persisted for 15 min. The effective dose was 0.2-0.5 mg/kg. Mean arterial blood pressure, total peripheral resistance and cardiac work were decreased, heart rate and cardiac output were increased. Cerebral metabolic rate of oxygen was enhanced. It is assumed that the compound has a direct effect on cerebral metabolism. RGH-4405 has a weak antiarrhythmic and coronary dilating activity. Its effect on smooth muscle is more marked than that of papaverine. RGH-4405 appears to be a potent cerebral vasodilator enhancing cerebral metabolism.