Chronic opioid therapy as alternative treatment for post-herpetic neuralgia.

Neurosurgical procedures such as the dorsal root entry zone operation, ganglionectomy, and spinal-cord stimulation have been offered to patients with intractable post-herpetic neuralgia (PHN). Poor efficacy or high morbidity have limited the overall usefulness of these procedures. We recently conducted a preliminary open-label study with long-acting oral opioids. The mean pretreatment pain score, on a scale of 0 to 10 (0 = no pain) was 9.0 +/- 0.3 (mean +/- SEM, N = 20). At two months of treatment the average pain score was 4.0 +/- 0.4 (p < 0.001, paired t test), and at six months the average pain score was 3.8 +/- 0.2 (p < 0.001, N = 16). These observations warrant a controlled opioid trial for patients affected by PHN.