An off-label gabapentin prescription did not reduce opioid dosage in patients with chronic opioid use, according to results of a retrospective cohort study published in Regional Anesthesia and Pain Medicine.
Researchers assessed 172,602 commercially insured patients with chronic opioid use who received a new off-label gabapentin prescription between January 1, 2010, and June 30, 2019.
Of the study cohort, 44.5% of patients were 65 years of age and older and 59.8% were women. Moreover, most patients had arthritis (82.3%) or back pain (68.5%). Approximately 28.7% had a diagnosis of anxiety and 19.4% had a diagnosis of alcohol or substance use disorder.
Opioid dosages were measured using oral morphine equivalents (OME) per day after adding the new off-label gabapentin prescription.
The new off-label gabapentin prescription was associated with a decrease in opioid dosage in 38.8% of patients 6 months after initiating the prescription (from a median of OME per day of 39.1 in the 6 months prior to the first off-label gabapentin prescription to a median OME per day of 25.3 in the 6 months after gabapentin initiation). An increase in opioid dosage was reported in 47.0% of patients (from a median OME per day of 23.2 in the 6 months prior to the first off-label gabapentin prescription to a median OME per day of 37.5 in the 6 months after gabapentin initiation.
There was no change in opioid dosage reported in 14.2% of patients.
Patients taking a new off-label gabapentin prescription who had a history of substance or alcohol use disorders had a decrease in opioid dosage (adjusted OR [aOR], 1.20; 95% CI, 1.16-1.23). Patients with pain disorders who were taking a new gabapentin prescription also had a decreased opioid dosage. This was observed in patients with arthritis (aOR, 1.12; 95% CI, 1.09-1.15); in those with back pain (aOR, 1.10; 95% CI, 1.07-1.12); and in those with other pain conditions (aOR, 1.08; 95% CI, 1.06-1.10).
Study limitations included causality between the addition of a new gabapentin prescription and a change in opioid dosage cannot be definitive due to the retrospective nature of the study. In addition, gabapentin and opioid prescriptions reflect fill rates but may not reflect actual consumption; further, the study of employer-sponsored health insurance claims may not be generalizable to recipients of Medicare and Medicaid, or the uninsured.
The authors concluded, “Findings from this study highlight concerns that off-label gabapentin prescribing in patients with chronic opioid use may not be offsetting opioid analgesia. In some patients, prescribers are not using off-label gabapentin to de-escalate opioid dosage and are contributing to high-risk coprescribing practices associated with respiratory depression and overall mortality.
This article originally appeared on Clinical Pain Advisor
Billig JI, Bicket MC, Yazdanfar M, et al. Cohort study of new off-label gabapentin prescribing in chronic opioid users. Regional Anesthesia & Pain Medicine. Published online June 27, 2023. doi:10.1136/rapm-2023-104613