A brief, high-dose remifentanil infusion partially reverses neuropathic pain in a subgroup of post herpetic neuralgia patients.

Mechanism-based therapy for chronic pain is desperately needed. Recent basic science research demonstrated that remifentanil can reverse long-term potentiation at C-fiber synapses in the dorsal horn of rats. In this exploratory, single group study, patients with chronic post-herpetic pain were treated with a single, one-hour, high-dose remifentanil infusion. The mean overall change of pain intensity seven days after treatment was -18 (-7.5; -28.5, 95%CI, p<0.001) points on the numeric rating scale (0-100) (-33 (±11) points amongst responders only). Eleven of 20 patients responded to treatment (≥30% reduction in pain), the mean relative reduction in pain from baseline amongst responders was 61.0%. These promising preliminary results suggest that a mechanism-based reversal of chronic pain may be impending.