Effectiveness, cost effectiveness and safety of gabapentin versus placebo as an adjunct to multimodal pain regimens in surgical patients: A placebo controlled randomised controlled trial with blinding (The GAP study)

Funder: NIHR/HTA (17/YH/0381)

Sponsor: University Hospitals Bristol and Weston NHS Trust

Status: In Analysis

About 4.5 million people undergo surgery each year in the UK. Most patients experience pain after surgery.  Good pain control is essential to recovery. Opioids (e.g. morphine) are typically prescribed to control the pain. Opioids are effective but carry side effects such as sleepiness, sickness and low blood pressure. These side effects prevent recovery and keep patients in hospital for longer. Gabapentin is an alternative medication that doctors are increasingly prescribing for pain relief after surgery. We don’t know whether giving gabapentin alongside opioids and other drugs improves pain control, leading to fewer side effects overall and a quicker recovery.  This is the question the GAP study is aiming to answer.

The GAP study recruited patients having heart, thoracic (e.g. lungs) or abdominal surgery. Patients who agreed to participate were allocated by chance to receive either gabapentin or identical-looking “dummy” pills (placebo) just before their operation and for two days following their operation. We collected information on pain experienced after surgery, the amount of opioid medications used, any complications patients experienced and how long patients stayed in hospital. We also collected information on quality of life and chronic pain experienced 4 months after surgery.

The GAP study is now in analysis, and results are expected to be ready later this year. You can find out more about what happens at the end of the study in this infographic: CTU Infographic_after participation

This study is funded by the National Institute for Health Research – Health Technology Assessment Programme (15/101/16). The views and opinions expressed therein are those of the author(s) and not necessarily reflect those of the National Institute of Health Research, NHS, or the Department of Health.

Patient Information Leaflet Appendix

Frequently asked questions about consenting to the GAP study remotely

Frequently asked questions about video calls

NIHR Award Information

Contact Information

Chief Investigator: Dr Ben Gibbison

Lead Applicant: Professor Chris Rogers

Study coordinator: Terrie Walker-Smith