Evidence of a central component in the analgesic effect of indoprofene.

1. The central nervous system effects of the analgesic antiinflammatory drug, indoprofene were studied. 2. CNS effects were found using EEG in rats and cats. 3. Evoked cortical potentials were studied in cats, and evoked activity in ventroposterolateral thalamic nucleus and laminae V of spinal cord were studied in rats. 4. Indoprofene induced a modification of all the parameters studied. 5. Evoked activity of thalamic nuclei and laminae V were significantly depressed. 6. Central effects were not antagonized by naloxone. 7. It is postulated that indoprofene has a central component in its effect, which would contribute to its strong and rapid analgesic effect.