CARDIOVASCULAR EFFECTS OF CROMAKALIM (BRL-34915) IN HEALTHY-VOLUNTEERS

1 The effect of oral doses of cromakalim 0.5, 1.0, 1.5 and 2.0 mg on several cardiovascular parameters was studied in healthy male volunteers. 2 In the first study, no dose of cromakalim reduced systolic or diastolic blood pressure in the supine or standing position. Reductions of diastolic blood pressure after exercise (P < 0.01) were observed 4 h after administration of 2.0 mg. 3 There was a trend towards increased heart rate after 2.0 mg at all time intervals, and significant changes were observed in supine and standing heart rate at 2 and 4 h (P < 0.01). No significant change was observed in exercise heart rate. 4 In the second study small increases in forearm blood flow were observed from 3 h to 5 h after oral administration of 1.0 and 2.0 mg of cromakalim. Forearm vascular resistance was significantly reduced after 2.0 mg (P < 0.025) when compared with placebo. No change was observed in forearm venous capacitance after either dose of cromakalim, or placebo. Supine heart rate was significantly increased 4 h after 2.0 mg of cromakalim (P < 0.025). 5 These results show that oral administration of cromakalim decreases diastolic blood pressure and forearm vascular resistance. A hypotensive effect is probably attenuated by reflex tachycardia.