From the Guidelines
Gabapentin is recommended over pregabalin for managing acute postoperative pain due to its efficacy in reducing pain scores and opioid consumption, as demonstrated in recent studies 1. When considering the management of acute postoperative pain, it's essential to weigh the benefits and risks of various medications.
Key Considerations
- Gabapentin has been shown to reduce postoperative pain scores and opioid consumption, with a high dose (> 900 mg daily) being superior in terms of pain scores 1.
- Pregabalin, on the other hand, has been found to reduce pain scores and morphine consumption in the post-anaesthetic care unit, but its effects do not last up to 24 hours 1.
- The choice between gabapentin and pregabalin should be based on institutional protocols, cost considerations, and patient-specific factors such as renal function and previous response to either medication.
Dosage and Administration
- Gabapentin is typically started at 300 mg three times daily and may be titrated up to 600 mg three times daily as needed.
- Pregabalin is usually dosed at 75-150 mg twice daily.
Side Effects and Precautions
- Common side effects of both medications include dizziness, sedation, and visual disturbances, which may be more pronounced in elderly patients or those with renal impairment, requiring dose adjustment.
- High doses of gabapentin may induce side effects that could be especially concerning in ambulatory patients 1.
Multimodal Pain Management
- Both gabapentin and pregabalin are most effective when started preoperatively (1-2 hours before surgery) and continued for 2-7 days postoperatively as part of a multimodal regimen.
- A combination of paracetamol, conventional NSAIDs or COX-2-selective inhibitors, and gabapentin is recommended for minor and major breast surgery, with the addition of local anaesthetic wound infiltration or paravertebral block for major surgery 1.
From the Research
Comparison of Gabapentin and Pregabalin for Acute Postoperative Pain Management
- Gabapentin and pregabalin are both used as adjuncts in the management of acute postoperative pain, with studies indicating their efficacy in reducing pain and opioid consumption 2, 3, 4.
- A systematic review and meta-analysis found that pregabalin reduced cumulative opioid consumption at 24 hours, with a significant decrease in opioid-related adverse effects such as vomiting 2.
- Another study found that gabapentin provided better post-operative analgesia and rescue analgesics sparing than placebo in 6 out of 10 RCTs, while pregabalin provided better post-operative analgesia in 2 out of 3 RCTs 3.
- A review of 22 randomized controlled trials found that gabapentinoids (gabapentin and pregabalin) effectively reduced postoperative pain, opioid consumption, and opioid-related adverse effects after surgery 4.
Efficacy of Gabapentin and Pregabalin in Reducing Opioid Consumption
- Gabapentin has been shown to reduce opioid consumption by 20-62% in the first 24 hours after surgery, with a combined effect equivalent to a reduction of 30 +/- 4 mg of morphine 4.
- Pregabalin has also been found to decrease opioid consumption, with a significant reduction in cumulative opioid consumption at 24 hours 2.
- A meta-analysis found that perioperative administration of gabapentin and pregabalin reduced the incidence of chronic postsurgical pain, with a pooled odds ratio of 0.52 for gabapentin and 0.09 for pregabalin 5.
Adverse Effects of Gabapentin and Pregabalin
- Common adverse effects of gabapentinoids include sedation and dizziness, with a number-needed-to-harm of 35 and 12, respectively 4.
- Pregabalin has been found to increase the risk of visual disturbance, with a risk ratio of 3.29 2.
- A systematic review found that perioperative pregabalin probably does not produce a clinically important decrease in acute postoperative pain, but may decrease nausea, postoperative vomiting, and opioid requirements, while increasing sedation 6.