Gabapentinoids have no analgesic effect on postoperative acute pain
Gabapentinoids, a class of drugs including gabapentin and pregabalin, was originally marketed in the 1990s for use as anticonvulsants and subsequently approved to treat specific chronic neuropathic pain conditions. Over the last decade, the off-label use of gabapentinoids for the control of acute nociceptive or neuropathic pain has drastically increased in several countries, and they are now routinely used for the management of postoperative analgesia to decrease pain and opioid use.
A recent study suggests that use of gabapentinoids does not yield a significant decrease in postoperative acute pain in adults but is associated with higher rates of visual disturbance and dizziness and longer length of hospital stay. The research has been published in the journal ANESTHESIOLOGY on August 2020.
The scientific data supporting the increased use of Gabapentinoids in a perioperative setup are divergent, which may reflect clinical agnosticism rather than new evidence of clinical effectiveness. Recommendations concerning the use of gabapentinoids for the management of postoperative pain are inconsistent. The American Pain Society (Glenview, Illinois) supports the perioperative use of gabapentinoids, while the European Society of Regional Anaesthesia and Pain Therapy (Geneva, Switzerland) does not. Recently, health authorities have raised serious concerns about potential adverse events (risk of abuse and respiratory depression) and net clinical benefit of gabapentinoids. Despite all this, the off-label use of gabapentinoids is still increasing worldwide. Therefore researchers of Canada conducted a systemic review and meta-analysis to evaluate the analgesic effect and adverse events with the perioperative use of gabapentinoids in adult patients.
It was a systemic review and meta-analysis of 281 clinical trials with 24,682 adult patients who underwent elective or emergent surgery. The major outcome assessed was the intensity of postoperative acute pain. Researchers also assessed the intensity of postoperative subacute pain, incidence of postoperative chronic pain, cumulative opioid use, persistent opioid use, lengths of stay, and adverse events as a secondary outcome.
Key findings of the study were:
• The researchers observed that gabapentinoids were associated with a lower postoperative pain intensity when compared with placebo at 6th,12th, 24th and 48th hour. However, they found the differences were not statistically significant ranging below the minimally important difference (10 points out of 100) for each time point.
• They found no difference in pain intensity between pregabalin and gabapentin.
• They also found that Gabapentinoids were not associated with the incidence of postoperative chronic pain.
• They noted Gabapentinoids slightly lower use of opioids at 24 hours (mean difference, −7.90 mg) and increases the length of hospital stay (mean difference, 2.96 hours).
• They reported less incidence of nausea/vomiting in Gabapentinoids group. However, they noted a significantly more visual disturbance (RR, 1.89) and dizziness (RR, 1.25)
The authors concluded, "No clinically significant analgesic effect for the perioperative use of gabapentinoids was observed. There was also no effect on the prevention of postoperative chronic pain and a greater risk of adverse events. These results do not support the routine use of pregabalin or gabapentin for the management of postoperative pain in adult patients".
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