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

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 infusion 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-intensive care unit.