The effects of nimodipine on cerebral blood flow and metabolism.

Nimodipine, a calcium entry blocker, was administered in increasing doses of 0.1-3.0 micrograms kg-1 min-1 to six dogs after they had recovered consciousness from a surgical preparation that was conducted under general anesthesia and while they were under the influence of total spinal anesthesia. CBF was measured with a sagittal sinus outflow technique and CMRO2 was calculated as the product of CBF and the arteriovenous O2 difference. Nimodipine did not influence either CBF or CMRO2. There was a decrease in the cortical pyruvate level at the end of the study, but no significant change in phosphocreatine, ATP, lactate, or energy charge when compared with six control dogs. It has previously been reported that nimodipine increases the CBF in global ischemia with a potentially beneficial effect on the neurological outcome. With no effect on normal CBF or metabolism, this suggests that nimodipine may be useful in a variety of ischemic situations without fear of either a steal phenomenon or untoward effects on intracranial pressure.