Doxepin as a blocker of central serotonin receptors.

The antidepressant drug-Doxepin (DX) was examined in order to investigate its central antiserotonin activity. The drug antagonized the behavioral syndrome elecited by L-5-hydroxytryptophan in rats and mice, but did not affect the pinna reflex. In the flexor reflex preparation, DX acted like other sero-tonin receptor blockers: By itself, it had no influence on the flexor reflex but it prevented the potentiation induced by serotonergic agents (fenfluramine, LDS, mescaline).