Open-label study of combination therapy with isoniazid for management of refractory neuropathic pain

Although there have been improvements in treatment, neuropathic pain often remains unresponsive to all treatment modalities. This pilot study assessed the efficacy of combination therapy with isoniazid for the treatment of intractable neuropathic pain. We conducted this prospective, open-label, add-on study in 45 consecutive patients who suffered from treatment-refractory neuropathic pain. The patients were given combination therapy with 8 mg/kg of isoniazid and were followed for a minimum of eight weeks. Pain relief was recorded using the visual analogue scale (VAS) score. Secondary measures included sleep interference scores and the Patient Global Impression of Change (PGIC) scale. There was a significant decrease in the mean VAS score following eight weeks of treatment compared with the baseline. In addition, PGIC and mean sleep score also improved. This study suggests that combination therapy with isoniazid has potent analgesic properties and may therefore be useful in the management of intractable neuropathic pain.