A once-daily extended-release formulation of Tramadolhydrochloride is a “robust analgesic” for treating osteoarthritis, results of a clinical trial suggest. “Significant differences from placebo were evident at week 1,” the authors report.

Tramadolis a recommended treatment for osteoarthritis pain that cannot be controlled adequately with nonopioid drugs, Dr. Najib Babul and associates report in the Journal of Pain and Symptom Management. However, it must be taken every 6 hours for optimal pain relief.

Babul, a pharmacologist at TheraQuest Biosciences in Blue Bell, Pennsylvania, and his team evaluated an extended-release formulation of Tramadolin patients with moderate to severe osteoarthritis of the knee.

The 12-week trial included 246 participants, who first underwent a period in which they discontinued all pain medication. They were then randomly assigned to extended release Tramadolor placebo.

The drug was initiated at 100 mg daily, increased to 200 mg/day between day 4 and day 8, then increased to 300 to 400 mg daily as needed.

“All efficacy outcome measures favored TramadolER over placebo,” the investigators write, including significant improvements in pain scores.

Measures of joint stiffness, physical function, and sleep were also better in the Tramadol-ER group, as were scores on the Patient and Physician Global Assessments of Therapy.

There were more adverse effects with Tramadol-ER, but the authors note that “the safety profile…is consistent with the known pharmacology of the drug.”

The authors recommend further clinical trials of ER Tramadolfor the treatment of other chronic pain conditions.

Journal of Pain Symptom Management, July 2004.