Effects of doxepin on perception of laboratory-induced pain in man

Abstract

Beneficial effects were observed in patients treated with tricyclic antidepressants, but such effects occurred much earlier than predicted mood elevation. To determine if doxepin, a tricyclic antidepressant, had analgesic properties healthy volunteers were tested over a 4-wk period during which they repeatedly performed Sensory Decision Theory tasks while undergoing painful dental stimulation. Doxepin and placebo were administered after baseline measurement for 4 wk under double blind conditions. No significant changes due to drug administration were observed in detection threshold or sensory sensitivity indices, but response bias against reporting the stimuli as painful changed dramatically after subjects began ingesting capsules. This effect was evident in both drug and placebo groups, and it was maintained across repeated wk of testing. The instructions given patients when the drug is administered have a profound effect on pain report.