[General pharmacology of 6-amino-2-fluoromethyl-3-(o-tolyl)-4(3H)-quinazolinone (afloqualone), a new centrally acting muscle relaxant. I. Effects on the central nervous system (author's transl)].

The general pharmacology of afloqualone, a new centrally acting muscle relaxant, in the CNS was examined in mice and rats and findings compared with those of other central muscle relaxants. Afloqualone showed relatively strong hexobarbital and barbital anesthesia potentiating action. Taking into account the dose ratio of anesthesia potentiating action to the muscle relaxing action, however, the potency of anesthesia potentiating action of afloqualone is lower than that of chlormezanone. At doses producing muscle relaxing action, afloqualone inhibited spontaneous motor activity, methamphetamine-induced hypermotility, pentylenetetrazol-, nicotine-, and maximum electroshock-convulsions, fighting episodes in foot-shocked mice, conditioned avoidance response in rat pole-climbing test, and acetic acid-induced writhing syndrome and lowered normal body temperature. The dose ratios of these pharmacological actions to muscle relaxing action of afloqualone, however, were larger than those of chlormezanone and mephenesin. This suggests that the central depressant activity of afloqualone is less potent and the specificity of muscle relaxing action of afloqualone is higher than those of climbing behaviour, physostigmine-induced death, serotonin-induced heat twitch, and reserpine-induced hypothermia, even at 50 mg/kg. Tolperisone showed neither muscle relaxing action nor other central actions when administered orally.