NEW YORK (Reuters Health) – The results of a placebo-controlled trial suggest that controlled-release oxycodone is an effective treatment for acute pain due to herpes zoster, whereas gabapentin is not.

Although the acute pain of herpes zoster can be severe and markedly impair quality of life, until now there have been no randomized trials that have specifically focused on the ongoing treatment of this problem with oral agents, according to the report in the April issue of the journal Pain.

“Oftentimes patients are told that the rash will heal in two or three weeks anyway, and the pain will go away, so they’re not given something for the pain unless it’s excruciating,” lead author Dr. Robert Dworkin said in a statement. “But moderate pain can stop people from working, or enjoying their hobbies, and it can also make some people depressed or anxious. So there’s good reason to treat all pain from the infection.”

In the new study, Dr. Dworkin, from the University of Rochester School of Medicine and Dentistry, New York, and colleagues assessed the pain-related outcomes of 87 patients who were randomized to receive controlled-release oxycodone, gabapentin, or placebo for 28 days. The subjects were at least 50 years of age, had pain scores of 3 or greater on a 10-point scale, and received 7 days of treatment with famciclovir.

Through treatment day 14, oxycodone was significantly better than placebo at reducing the average worst pain (p < 0.05). This was not the case through 28 days, primarily due to the fact that by that time, the pain had resolved in most subjects any way. As noted, gabapentin was not significantly better than placebo for pain relief, although there was evidence of modest benefit during the first week of treatment. Oxycodone and gabapentin were adequately tolerated and their adverse effects were in line with those previously reported for the agents. Subjects treated with oxycodone were significantly more likely than placebo users — 27.6% vs. 6.9% — to discontinue trial participation, usually due to the occurrence of constipation. “By demonstrating that controlled-release oxycodone is safe, generally adequately tolerated, and efficacious in relieving acute pain in patients with herpes zoster, the results of this clinical trial provide a foundation for evidence-based treatment for herpes zoster pain,” the authors conclude. Reference:
Pain 2009;142:209-217.