Postherpetic neuralgia (PHN) is the most common problem of acute herpes zoster with many patients still facing unbearable pain conditions. This randomized controlled trial supported the use of hydromorphone IV PCA plus oral pregabalin for pain relief due to PHN.

To investigate the efficacy of hydromorphone via intravenous patient-controlled analgesia  (IV PCA) for PHN management.

Total 201 patients were divided into two groups as:

• Control group with oral pregabalin with normal saline IV,
• Hydromorphone group with oral pregabalin with added hydromorphone IV PCA for 14 days

Efficacy was assessed at 1 week, 4 weeks, and 12 weeks follow-up.

As compared to control group, the patients in the hydromorphone group had a significantly lower numerical rating scale (NRS) score, and the difference of NRS scores between the these groups was statistically significant at 4 weeks and 12 weeks following the therapy. Occurrence of breakthrough pain in the hydromorphone group was significantly lower than control group at 1 week and 4 weeks. Also, an improved sleep quality was observed in hydromorphone group. Dizziness and nausea were commonly reported advserse events.

Combination of hydromorphone  IV PCA and oral pregabalin offers superior pain relief in PHN patients.