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.
An open and double-blind cross-over study on the efficacy of clomipramine (Anafranil) in patients with painful mono- and polyneuropathies.
82 patients with chronic pain resulting from mononeuropathy were treated with psychotropic drugs in an open therapeutic study. In this study we found that treatment with a combination of clomipramine (Anafranil) and small doses of neuroleptics was significantly superior to therapy with neuroleptics alone. In a subsequent double-blind study, it was attempted for the first time to determine the efficacy of clomipramine compared to that of acetylsalicylic acid in 48 patients with painful mono- and polyneuropathies. The test was carried out in a cross-over trial with two sequence groups. We evaluated assessments of pain by both patients and doctors, and were able to prove statistically that clomipramine possesses a significantly greater efficacy compared to that of acetylsalicylic acid. By taking into account recent anatomical, biochemical and pharmacological studies, it can be concluded that clomipramine probably has-in addition to the action on peripheral receptors-a direct effect upon pain modulation systems. It seems possible that clomipramine activates serotonin-containing neurons of the endorphin-mediated analgesia system that control pain transmission in the CNS.