Many Options for Diabetics' Pain

Diabetics often experience peripheral neuropathy. In an estimated 30% to 50% of patients, this condition results in pain. The most common painful neuropathy is distal symmetric sensorimotor polyneuropathy.

Physicians have many options in trying to help these patients. In a new study in the November 2014 Annals of Internal Medicine, Marcio Griebeler, MD and colleagues evaluated the literature on what pharmaceutical remedies appeared to work to provide these patients relief.

They looked at 65 randomized controlled trials involving 12,632 pharmacologic treatments for patients with painful diabetic neuropathy.

“The comparative effectiveness of treatment regimens that include step wise approaches is unclear, partially because of the scarcity of direct head-to-head trials,” they wrote.

The authors conducted a systematic review and network meta-analysis to summarize and appraise the totality of evidence from randomized, controlled trials about the efficacy of the most commonly used oral and topical analgesics.

Of all the journal articles they found, only 9 involved head-to head trials of remedies.

Their analysis found that several analgesic may be effective for short-term treatment.

Selective serotonin reuptake inhibitors (SNRIs) topical capsaicin, tricyclical antidepressants (TCIs), and anticonvulsants all achieved significant reductions in pain. “SNRIs had a greater effect on pain control than anticonvulsants and opioids,” the researchers wrote.

All the therapies also had side effects. Patients who got TCAs, SNRIs, and most anticonvulsants reported sleepiness and dizziness. Additionally, those who took TCAs reported xerostomia. Patients on SNRIs reported nausea, constipation, and dyspepsia.

Topical capsaicin was frequently associated with burning at the application site.

Even after their extensive review of existing studies, the authors found knowledge gaps.

“The few head-to-head trials, heterogeneity of results, and substantial proportion of trials at high or uncertain risk of bias warrant caution in our confidence in the estimates of comparative effectiveness among these agents,” the authors wrote.

Another problem they noted was that most of the studies had little or no information about what agents worked for longer than 3 months.

The study was funded by the Mayo Foundation for Medical Education and Research.