This update has provided additional confirmation on the effectiveness of antidepressants for neuropathic pain and has provided new information on another antidepressant - venlafaxine. There is still limited evidence for the role of SSRIs. Whether antidepressants prevent the development of neuropathic pain (pre-emptive use) is still unclear. Both TCAs and venlafaxine have NNTs of approximately three. This means that for approximately every three patients with neuropathic pain who are treated with either of these antidepressants, one will get at least moderate pain relief. There is evidence to suggest that other antidepressants may be effective but numbers of participants are insufficient to calculate robust NNTs. SSRIs are generally better tolerated by patients and more high quality studies are required.
Amitriptyline and fluphenazine in the treatment of postherpetic neuralgia.
Postherpetic neuralgia (PHN) is a vexing problem occurring in 10 to 20 percent of people with from herpes zoster (shingles). Anecdotal reports show that fluphenazine enhances the effects of amitriptyline for the treatment of PHN. The aim of this study was to determine, in a controlled manner, whether this was the case.
                In a double-blind placebo-controlled study, 49 patients with PHN were randomly assigned to four treatment groups: Group 1, amitriptyline; Group 2, amitriptyline and fluphenazine; Group 3, fluphenazine; Group 4, a placebo. An active placebo was used to mimic the anticholinergic side effects of dry mouth. The study lasted 8 weeks, with weekly progress evaluations with use of visual analog scales (VAS), the McGill Pain Questionnaire (MPQ), and a side-effects scale.
                A statistically significant decrease was seen in pain in Groups 1 and 2, and no significant changes were seen in Groups 3 and 4. There was no significant difference when fluphenazine was added to amitriptyline.
                These data support the effectiveness of amitriptyline in treatment of PHN, but do not support the addition of fluphenazine.