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 in diabetic neuropathy: relief of subjective symptoms without changes in peripheral and autonomic nerve function.
The effect of imipramine on symptomatic peripheral diabetic neuropathy in 9 patients was examined in a double-blind cross-over study against placebo. The dose of imipramine was adjusted to yield optimal plasma levels of imipramine plus desipramine of 300-750 nM. Imipramine had a clear beneificial effect on the symptoms of the neuropathy, whereas no changes in a range of neurophysiological measurement was detected. Despite some adverse effects, especially of an anticholinergic nature, the patients generally preferred imipramine to placebo.