THE EFFECT OF KETANSERIN ON CEREBRAL BLOOD-FLOW AND OXYGEN-METABOLISMIN HEALTHY-VOLUNTEERS

The effect of the anti-hypertensive agent ketanserin on average global cerebral blood flow (CBF) and average global cerebral oxygen metaboli sm (CMRO2) was examined in 8 healthy volunteers. CBF and CMRO2 were me asured with the Kety-Schmidt technique before ketanserin administratio n (baseline) and after administration of 2 different doses of ketanser in intravenously (dose I: 10 mg bolus and an infusion of 6 mg/h; dose II: 20 mg bolus and an ifusion of 20 mg/h). Baseline CBF and CMRO2 wer e 60 and 3.6 ml/100 g/min, respectively, and were not changed by admin istration of ketanserin dose I. During administration of dose II, howe ver, CBF fell to 52 ml/100 g/min (p = 0.05) and CMRO2 was reduced to 3 .2 ml/100 g/min (p < 0.05). We conclude that when administered in a hi gh dose, ketanserin has the ability to depress cerebral oxygen metabol ism, but when administered in a clinically relevant dose ketanserin do es not influence average global CBF or average global CMRO2. Ketanseri n could be a safe antihypertensive drug in neuroanaesthesia or in the neuro-intesive care unit.