Intracranial effects of nicardipine

Preliminary investigations indicated that the calcium antagonist nicardipine improved cerebral vascular circulation and cerebral metabolism. Therefore we examined the effect of nicardipine on the cerebral vessels, cerebral oxygen tension, and intracranial pressure (ICP) in patients with cerebrovascular disturbances. In patients with previous minor stroke undergoing surgery for extra-intracranial anastomosis, we applied nicardipine topically to the operation site by means of a perfusor and measured the diameter of the cerebral vessels. After several minutes, the topically applied nicardipine produced marked dilatation in the small arterial cortical vessels and relaxation of vasospasm. In the two patients studied so far, we observed a rapid increase in the cerebral PO2, which remained elevated after the initial peak as long as the infusion continued. With a lower dose the increase in the intracranial pulse amplitude (PAICP) was antagonized by the considerable drop in blood pressure which occurred after 10 mg h-1 nicardipine. The results indicate that nicardipine dilates the cerebral vessels and increases the cerebral oxygen tension.