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.
Double-blind, randomized trial of bupropion SR for the treatment of neuropathic pain.
To evaluate the effectiveness and safety of bupropion sustained-release (SR) for the treatment of neuropathic pain.
                This single-center, outpatient, randomized, double-blind, placebo-controlled, crossover study consisted of two phases. Forty-one nondepressed patients with neuropathic pain spent 6 weeks in each phase in random order and received identical tablets of 150 mg bupropion SR or placebo. Patients were instructed to take one tablet once daily for 1 week followed by one tablet twice daily for 5 weeks.
                While the patients took bupropion SR, neuropathic pain relief was improved or much improved in 30 (73%) patients, and one of these patients became pain-free. The mean average pain score at baseline was 5.7, which remained unchanged at the end of week 6 with placebo, but decreased by 1.7 points to 4.0 (p < 0.001) during therapy with bupropion SR. Pain relief with bupropion SR was significant at week 2 (p < 0.05) and continued throughout weeks 3 through 6 (p < 0.001). A significant decrease in interference of pain on quality of life was observed while patients were receiving bupropion SR compared with placebo. Side effects experienced with bupropion SR were not dose-limiting and consisted primarily of dry mouth, insomnia, headache, gastrointestinal upset, tremor, constipation, and dizziness.
                This placebo-controlled crossover trial showed that bupropion SR (150-300 mg daily) was effective and well tolerated for the treatment of neuropathic pain.