To the Editor:
Two complementary phase 3 trials in the March/April 2008 issue help define the role of controlled-release tramadol in the management of pain from osteoarthritis. Thorne et al compared tramadol to placebo, and Beaulieu et al compared tramadol to diclofenac. Both authors commented on the conventional use of nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen. Beaulieu et al reminded us that NSAIDs were shown to be equivalent to acetaminophen in osteoarthritis pain. Both authors mentioned the toxicity of NSAIDs, but both seemed to avoid mentioning the possibility that tramadol offers no advantage over acetaminophen. It does have some toxicity and considerably more cost.
While a placebo trial is scientifically desirable, reading these two articles together begs the need for a comparison with acetaminophen. I note that the corresponding author of both articles is an employee of Purdue Pharma. I suspect Purdue Pharma will not be interested in sponsoring such a trial, but I would be happy to be proven wrong. Patients, and perhaps doctors, will tend to believe that the more expensive prescription drug must be more effective, but I believe that for now, the role for tramadol should remain rather small.