Three phase 3 clinical trials of tramadol showed that the safety and efficacy of the once-daily formulation offers a safe alternative for the management of pain. The drug's manufacturer, Labopharm, presented data at the 17th Annual Clinical Meeting of the American Academy of Pain Management in September 2006. The 12-week, randomized, double-blind, placebo-controlled trials included 1763 patients with osteoarthritis of the knee. Doses ranging from 100 to 300 mg were randomized to 1095 patients, while 668 patients received placebo. The most frequent adverse events reported were nausea, constipation, dizziness/vertigo, somnolence, and vomiting. Adverse events appeared in at least 5% in all doses, but 90% of these events were reported to be mild or moderate. When compared with other formulations of tramadol, traditional opioids, and nonsteroidal anti-inflammatory drugs, the once-daily tramadol offered a safe alternative for pain management.

Ms. Farley is a freelance medical writer based in Wakefield, RI.