Wong MC et al. (2007) Effects of treatments for symptoms of painful diabetic neuropathy: systematic review. BMJ 335: 87

Patients with diabetic neuropathy often report neuropathic pain. Treatment for these patients involves tight glycemic control to slow the progression of diabetic neuropathy and the administration of analgesics, commonly antidepressants and anticonvulsants, to reduce the intensity of neuropathic pain. Wong et al. carried out a systematic review to assess the effectiveness of different analgesics in treating diabetic neuropathy in adults.

The authors searched scientific databases and identified randomized, controlled trials that compared topically applied or orally administered analgesics with placebo. From this search, 25 English language full-text articles were identified that met the inclusion criteria; after further exclusion on the basis of suitability of data for analysis, 17 studies were included in the meta-analysis of treatment efficacy. The primary outcome was an approximate 50% reduction in pain as a result of treatment. Tricylic antidepressants, traditional anticonvulsants and opioids were found to be better for short-term pain relief than were newer generation anticonvulsants, a selective serotonin reuptake inhibitor and a serotonin noradrenaline reuptake inhibitor.

The authors provide a treatment algorithm for painful diabetic neuropathy on the basis of their findings, but stress that the studies they reviewed involved only short-term treatment (<6 months). The review also highlighted the lack of, and need for, studies on the long-term effects of anticonvulsants and antidepressants, which are widely used to treat these patients.