Gabapentin

Four high level studies (Lunn 2015; Paul 2013; Paul 2015; Clarke 2014) evaluated multi-dosed perioperative oral gabapentin.  Lunn 2015 looked at high dose (1300mg/d) and low dose (900mg/d) gabapentin protocol consisting of a single preoperative dose through 7 days post operatively in TKA.  Sleep quality was better in the first 48 hrs. in both gabapentin groups, but no differences were seen in overall pain (only VAS pain at rest) or morphine used.  Furthermore, dizziness was more frequently observed in both gabapentin groups leading the authors to conclude that gabapentin may have a limited role in multimodal TKA pain control and should not be recommended as standard of care. The CPG group agrees with the authors of these studies that routine clinical use of gabapentin should be avoided outside of controlled clinical research scenarios allowing for gabapentin’s potential use in future multimodal pain regimens.

Paul evaluated pre- (600mg) and post-operative (200mg TID) gabapentin in both TKA (2013) and THA (2015) and found no differences in pain, ROM, morphine consumption, satisfaction, or length of stay in either cohort.  It is worth noting that Paul 2013 did not use any femoral or adductor canal nerve blocks and but did utilize post-operative PCA and spinal anesthesia.

Clarke 2014 utilized a PCA, spinal anesthesia, femoral and sciatic nerve blocks in addition to 600mg pre- and 200mg TID post-operative gabapentin (or placebo) for 4 days in a TKA population.  The gabapentin group used significantly less morphine in the first 24 hrs. and increased in hospital knee ROM (secondary outcomes).  No differences were seen in pain or physical function at 4 days, 6 wks., and 3 months after surgery (WOMAC score was primary outcome).  The placebo group had significantly more nausea and pruritus (possible opioid side effect) compared to the gabapentin group on POD 1 and dizziness on POD 3.

Two high quality studies (Clarke 2009; Panah Khahi 2012) looked at single dose gabapentin given either before or after surgery.  Clarke (2009) looked at single dose gabapentin (600 mg) either before or after THA and found no difference in pain scores or morphine consumption.  Similarly, Panah Khahi (2012) looked at single dose gabapentin (300 mg) following ORIF of a tibia fracture and found no difference in pain or morphine consumption.

Feasibility

Gabapentin is FDA off label use for perioperative pain.

Future Research

Research would benefit from further well-constructed trial looking at gabapentin in the TKA population in the presence of adductor canal blocks, dosed both pre-and post-operatively in a variety of patient populations beyond TJA, and with studies powered for primary outcomes looking at pain, narcotic use, adverse events, sleep quality, and function.