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.
Imipramine treatment of painful diabetic neuropathy.
Twelve patients with severe, painful diabetic neuropathy in the lower extremities were treated with imipramine and placebo in a fixed-dose, double-blind, crossover study of five plus five weeks. Seven patients experienced notable improvement while receiving imipramine and none while receiving placebo. The rating of specific symptoms at the end of each treatment period showed a beneficial effect of imipramine on pain, paresthesia, dysesthesia, numbness, and nocturnal aggravation. The plasma levels of imipramine and its metabolite desipramine were significantly higher in patients who benefited from imipramine treatment.