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The following is a summary of “Post-Amputation Pain: Combined Analyses of Randomized Controlled Trials Evaluating Opioids and Gabapentinoids versus Placebo,” published in the October 2024 issue of Pain by Arthur et al.
In the United States, an estimated 1,85,000 patients underwent extremity amputations annually, with nearly 50% experiencing prolonged postoperative opioid use, which was linked to preoperative use of benzodiazepines, muscle relaxants, anticonvulsants, and antidepressants.
Researchers conducted a retrospective study to examine the efficacy of selected pharmacologic agents in managing the post-amputation pain and success rates.
They screened the literature available on PubMed for articles employing randomized-controlled trial (RCT) designs that investigated gabapentinoids (e.g., gabapentin or pregabalin) or opioids (e.g., morphine), 2 RCTs related to morphine that utilized at least 50% pain reduction responder criteria were combined and qualitatively compared with 2 gabapentin trials previously analyzed to assess the potential benefits of the medications in managing post-amputation pain vs placebo.
The results showed that all 4 trials assessed post-amputation pain during a 4- to 6-week acute period. The combined analysis of opioids revealed a treatment effect favoring morphine (P =0.02) over placebo, with a number needed to treat (NNT) of 3.9 (95% CI: 2.5, 9.3) patients. Likewise, the earlier combined analysis of gabapentin trials also indicated a preference for gabapentin over placebo, yielding an estimated NNT of 8.9 (95% CI: 5.3, 27.8).
They concluded the patients undergoing limb amputation require enhanced chronic pain management, with more extensive and longer-term controlled trials to evaluate the benefits and drawbacks of gabapentinoids and opioid combination therapies in the population.