Patients with sciatica have radiating posterior or posterolateral leg pain that may also be accompanied by back pain. Unfortunately, with or without low back pain, sciatica can be disabling, due to the lack of established treatments. Fortunately, most sciatica resolves over time.
Studies have shown that pregabalin can be an effective treatment for some types of neuropathic pain, particularly postherpetic neuralgia and diabetic peripheral neuropathy. Thus, pregabalin represents a potential treatment for sciatica. Researchers have investigated the ability of pregabalin to treat sciatica and, although recent study results have been conflicting previous studies have suggested that patients with chronic low back pain or sciatica do not respond well to pregabalin or gapabenting. In addition, large-scale studies of pregabalin for neuropathic pain had negative results or shown minimal effect. A meta-analysis concluded that for one patient to achieve 50% pain relief from pregabalin, 7.7 patients would need to be treated, explains Nadine Attal, MD, PhD, associate professor of neurology at the Universite Versailles-Saint-Quentin, France, and Michel Barrot, PhD, research director at the Institut des Neurosciences Cellulaires et Intégratives (INCI) at the Universite de Strasbourg, France, in an editorial in the March 23 issue of The New England Journal of Medicine.1
New research published in the same issue reinforces the understanding that pregabalin treatment does not significantly reduce the intensity of leg pain associated with sciatica.2 Stephanie Mathieson, M Chiro, a graduate student at Sydney Medical School in Australia, and colleagues conducted the prospective, double-blind, placebo-controlled trial of 209 patients with moderate to severe sciatica of varying durations. Many of the patients had experienced symptoms for less than three months. At baseline, leg pain was most commonly related to the first sacral root, and dermatomal pain was more common than neurologic deficit. Approximately one-third of the patients in the study had probable characteristics of neuropathic pain at baseline.
The researchers enrolled patients from 47 sites, and trial clinicians dosed pregabalin (150–600 mg) individually, on the basis of a patient’s progress and side effects. Approximately 74% of patients in each group adhered to the dosing schedule, which the authors considered a high adherence rate. The primary outcome of the study was leg-pain intensity score at Week 8 and Week 52. The secondary outcomes were extent of disability, back-pain intensity and quality-of-life measures.
The one-year study compared pregabalin with placebo and found no significant improvements in any of the documented outcomes. Unfortunately, however, the incidence of adverse events was significantly higher in the group treated with pregabalin than in the placebo group. Example: Dizziness was more common in the pregabalin group than the placebo group. The incidence of serious adverse events was no different between the two groups and was similar to what has been documented in previous clinical trials. It’s important to note that the investigators did not find a higher rate of suicidality in patients treated with pregabalin.