The analgesic effect of amitriptyline on chronic facial pain

The efficacy of amitriptyline was evaluated in 28 patients with chronic oral-facial pain. Most of the patients had evidence of musculoskeletal pain while some had a history suggesting pain of neurogenic origin. Two patients had mixed elements of neurogenic and musculoskeletal pain. Amitriptyline was more effective than placebo in reducing pain after 4 weeks of treatment. No effect was found after only 1 week of drug administration in either dose range. When the patients were divided into depressed and non-depressed groups based on their Hamilton depression scores, amitriptyline reduced pain in the depressed and in the non-depressed groups as compared to placebo. Amitriptyline reduced the depression scores in the depressed group but had no effect on the depression scores in the non-depressed group. Thus, pain reduction was not associated with a change in mood in the non-depressed group. Amitriptyline had no effect on patients' ratings of the intensity of experimental heat stimuli. We conclude that amitriptyline is effective in the treatment of chronic oral-facial pain and that its efficacy is independent of its effects on depression. It appears that tricyclic antidepressants act in a fashion different from opiate drugs that alter the sensory discriminative component of pain.