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.
The selective serotonin reuptake inhibitor citalopram relieves the symptoms of diabetic neuropathy.
The effect of the selective serotonin reuptake inhibitor citalopram on diabetic neuropathy symptoms was examined in a double-blind, placebo-controlled, crossover study for two 3-week periods. Citalopram was given as a fixed dose of 40 mg/day. Data from 15 patients could be included in the statistical analysis. Citalopram significantly relieved the symptoms of neuropathy as measured by both observer- and self-rating in comparison with placebo. The steady-state plasma concentration of citalopram was 10 to 890 nmol/L. There was no significant relationship between the plasma concentration of citalopram and the effect of treatment as measured by observer- or self-rating. Two of 17 patients, both receiving citalopram, left the study because of side effects (nausea and vomiting or gastric upset and diarrhea). Side-effect ratings were significantly higher during administration of citalopram than during administration of placebo, but citalopram was generally well tolerated. Compared with earlier results obtained with imipramine administered on the basis of plasma level monitoring, citalopram appeared to be less effective, but seemed to be better tolerated.