Effectiveness of Gabapentin in Reducing Opioid Requirements after Radiation in Head and Neck Cancer in a Single Institution

Abstract

<h3>Purpose/Objective(s)</h3> The national opioid epidemic has been an increasing health crisis over the last 3 decades. Head and neck cancer patients are at risk for chronic opioid use due to pain from their disease or treatment. Studies have evaluated the effectiveness of gabapentin to mitigate opioid use in this population. In this study, we aim to examine the efficacy of prophylactic gabapentin at our institution to reduce opioid use in head and neck cancer patients receiving radiation therapy. <h3>Materials/Methods</h3> A prospective cohort study of patients receiving radiation therapy (RT) for head and neck cancer was performed. Patients from a previous publication from our institution not treated with gabapentin were used as controls. Sociodemographic and clinical information was recorded, including if patients were taking opioids at 3 and 6-months after therapy, which was the primary endpoint of the study. Factors related to chronic opioid use were evaluated with univariate and multivariate analyses. <h3>Results</h3> In total, 185 patients met inclusion criteria, 53 being treated with gabapentin. Overall, 39.6% of patients taking gabapentin were using opioids at 3 months post-treatment vs. 58.3% in the non-gabapentin cohort (p= 0.021). There was no statistical difference between cohorts at 6 months. Gabapentin use was independently associated with less opioid use on multivariate analysis at 3 months, but not at 6 months (p=0.049, 95% CI 0.01-0.62). Gabapentin patients were 47% as likely to use opioids at 3 months (OR 0.47, 95% CI 0.24-0.9) than those not treated with gabapentin. Perineural invasion on pathology specimens was not significantly associated with opioid use in the gabapentin cohort. Gastrostomy tube dependence and pre-treatment opioid use were associated with chronic opioid use despite gabapentin treatment on both univariate and multivariate analyses. <h3>Conclusion</h3> Gabapentin is an effective medication at expediting opioid tapering in head and neck cancer patients who were not taking opioids pre-treatment or gastrostomy tube dependent. These patients are particularly high risk for chronic opioid use, and gabapentin treatment should be approached with caution as it is less likely to be effective, and these patients are at higher risk for medication abuse.