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.
Trazodone in burning mouth pain: a placebo-controlled, double-blind study.
An 8-week parallel, placebo-controlled, double-blind trial evaluated the efficacy of the antidepressant trazodone in the treatment of chronic burning mouth pain.
                Thirty-seven carefully selected women aged 39 to 71 (mean 58.6 years) were randomized to receive either 200 mg of trazodone or a placebo in a similar manner. Pain and pain-related symptoms were evaluated on a visual analogue scale and other measures at 0, 2, 4, and 8 weeks.
                There were no significant differences between the groups in treatment effects for pain or pain-related symptoms. Seven patients in the trazodone group and 2 in the placebo group failed to complete the trial because of side effects. The most common side effects were dizziness and drowsiness.
                In this controlled trial, trazodone failed to relieve burning mouth pain.