Trazodone hydrochloride attenuates thermal hyperalgesia in a chronic constriction injury rat model.
OBJECTIVE
Trazodone hydrochloride is used in the treatment of neuropathic pain. However, the analgesic effects of trazodone on neuropathic pain are controversial. The study was undertaken to determine the analgesic effect of trazodone on a chronic constriction injury model.


METHODS
We tested the effect of trazodone on thermal hyperalgesia due to a chronic constriction injury of the sciatic nerve in rats and examined the effects of lesions in the descending and ascending serotonergic system induced by 5,7-dihydroxytriptamine (5,7-DHT).


RESULTS
The analgesic effects of trazodone showed a clear dose dependency. Furthermore, the analgesic effect of trazodone was observed in rats injected with 5,7-DHT into the dorsal raphe nucleus and medial raphe nucleus.


CONCLUSIONS
The results suggest that a mainly serotonergic descending pain control pathway mediates the analgesic effects of trazodone.
Okuda
K
K
Dokkyo University School of Medicine, Department of Anaesthesiology, Mibu, Tochigi, Japan. y-okuda@dokkyomed.ac.jp
Takanishi
T
T
Yoshimoto
K
K
Ueda
S
S
D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use*; D004195:Disease Models, Animal; D006358:Hot Temperature / Q000009:adverse effects; D006930:Hyperalgesia / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries*; D020196:Trauma, Nervous System / Q000150:complications; D014196:Trazodone / Q000627:therapeutic use*
D018687:Antidepressive Agents, Second-Generation; D014196:Trazodone