Can gabapentin be used for postoperative pain in adult patients undergoing moderate‑to‑major surgery, and what are the recommended dosing regimens for standard, elderly/frail, and renally impaired patients?

Gabapentin for Postoperative Pain: Limited Clinical Utility

Gabapentin should not be routinely used for postoperative pain management in adults undergoing moderate-to-major surgery, as the analgesic benefit is statistically significant but clinically insignificant, and it carries meaningful risks of sedation, dizziness, and visual disturbances. 1

Evidence Against Routine Use

The most comprehensive and recent meta-analysis of 281 trials involving 24,682 participants demonstrates that gabapentinoids provide pain reduction below the minimally important difference threshold at all postoperative time points 1:

• 6 hours post-op: 10-point reduction on 100-point scale (at threshold)
• 12 hours: 9-point reduction (below threshold)
• 24 hours: 7-point reduction (below threshold)
• 48 hours: 3-point reduction (well below threshold)
• 72 hours and beyond: No effect 1

Critically, gabapentinoids showed no effect on preventing chronic postoperative pain, which is often cited as a rationale for their use 1.

Specific Dosing Evidence Shows Poor Efficacy

For gabapentin 250 mg as a single dose, the number-needed-to-treat (NNT) for 50% pain relief is 11, which is clinically inferior to standard analgesics like NSAIDs or acetaminophen 2. Higher doses (900-1300 mg/day) in total knee arthroplasty showed no difference in pain scores compared to placebo but significantly increased sedation 3.

Guideline Recommendations

The 2021 British Journal of Anaesthesia guidelines on perioperative opioid use recommend that patients already on gabapentinoids should have indications reviewed and the medication tapered if no longer indicated 4. This suggests a conservative approach rather than routine initiation.

The 2025 PROSPECT guidelines for total knee replacement explicitly state that pregabalin (gabapentin's analog) is not recommended for routine use due to clinically relevant side effects that outweigh benefits 5.

Procedure-Specific Exception: Breast Surgery

The only context where gabapentin shows reasonable evidence is oncological breast surgery, where preoperative gabapentin 900+ mg reduced pain scores in PACU and at 24 hours, with high-dose gabapentin (≥900 mg daily) showing superior results 4. However, even here, pregabalin showed benefit only in PACU but not at 24 hours 4.

Adverse Effect Profile

Gabapentinoids consistently increase risk of 1:

• Dizziness (significant increase)
• Visual disturbances (significant increase)
• Sedation (dose-dependent, particularly problematic in elderly)

While they reduce postoperative nausea and vomiting compared to opioids alone, this benefit does not outweigh the CNS side effects 1.

When Gabapentin May Be Considered

For post-surgical neuropathic pain specifically (not routine postoperative pain), pregabalin started within 2 days postoperatively and continued for 3 months reduced chronic neuropathic pain incidence from 41.3% to 19.6% following thoracic surgery 6. This is a distinct indication from acute postoperative pain management.

Dosing for Neuropathic Pain (Not Routine Postoperative Pain):

• Standard patients: Start 75 mg twice daily, titrate to 150 mg twice daily within first week 6
• Elderly/frail patients: Start 25-50 mg daily with slower titration 6, 7
• Renal impairment: Dose reduction required (gabapentin is renally cleared) 4, 6

Clinical Algorithm

For routine postoperative pain:

1. Use multimodal analgesia with acetaminophen + NSAIDs as foundation 4
2. Add immediate-release opioids (oral morphine preferred) when simple analgesics insufficient 4
3. Do not routinely add gabapentin 1, 3

For suspected neuropathic component:

1. Identify neuropathic features (burning, shooting, electric-like pain) 7
2. Consider pregabalin over gabapentin (better evidence) 6
3. Combine with opioids, not as monotherapy 6
4. Continue minimum 3 months if preventing chronic pain 6

Critical Pitfall to Avoid

Do not prescribe gabapentin simply to reduce opioid consumption—while it achieves modest opioid-sparing effects, the clinical pain relief does not meet minimally important difference thresholds, and the sedation/dizziness risks may actually impair recovery and increase fall risk, particularly in elderly patients 1, 3.