The effect of ketanserin on cerebral blood flow and oxygen metabolism in healthy volunteers

Summary The effect of the anti-hypertensive agent ketanserin on average global cerebral blood flow (CBF) and average global cerebral oxygen metabolism (CMRO₂) was examined in 8 healthy volunteers. CBF and CMRO₂ were measured with the Kety-Schmidt technique before ketanserin administration (baseline) and after administration of 2 different doses of ketanserin 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 were 60 and 3.6 ml/100 g/min, respectively, and were not changed by administration of ketanserin dose I. During administration of dose II, however, 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 high dose, ketanserin has the ability to depress cerebral oxygen metabolism, but when administered in a clinically relevant dose ketanserin does not influence average global CBF or average global CMRO₂. Ketanserin could be a safe antihypertensive drug in neuroanaesthesia or in the neuro-intesive care unit.