Influence of piracetam and etiracetam compared to placebo, on rCBF and parameters of brain metabolism.

On occasion of a carotid angiography in man, regional cerebral bloodflow (rCBF) was measured before and after the injection of thiopental 5 mg/kg I.V. A significant decrease of rCBF was found after thiopental, in a previous study, due to a decrease of the brainmetabolism. To study the influence of piracetam and of etiracetam on this decrease of rCBF, 22 patients received intravenously the evening before the investigation 4 g piracetam or 4 g etiracetam or placebo, as well in the morning before the investigation and 30 minutes before the injection of thiopental. Besides the rCBF also other parameters were measured: arterial pressures, cardiac output, heart rate, as well as blood gases, glucose, lactate and pyruvate in the arterial blood and the cerebral venous blood, and blood gases in the mixed venous blood. There was no influence on the decrease of rCBF neither in the piracetam or etiracetam group, compared to the placebogroup. A few scarce minor changes were seen in the other measured parameters.