[Inhibition of morphine hyperthermia, induced by nicotinamide]

The effect of nicotinamide, administered immediately before the morphine or on the background of already developed morphine hyperthermic reaction, was studied on morphine hyperthermia. It was established that nicotinamide, administered before morphine, inhibited development of morphine hyperthermia, statistically significantly up to 120 min after administration of morphine. Nicotinamide, administered, on the 60th min after morphine injection, did not inhibit significantly the developed already hyperthermic reaction. In connection with the discussion of the established effects a series of experiments were carried out on N-demethylation of morphine and nicotinamide influence on in vitro. These experiments proved that nicotinamide inhibited noncompetitive demethylation of morphine.