OBJECTIVES: Increasing use of gabapentinoids (i.e., gabapentin and pregabalin) has raised concerns of misuse and abuse of gabapentinoids in the US. Yet, little is known about the patient and prescriber characteristics of gabapentinoid use. This information may be valuable to better inform target interventions in the general clinical practice, where chronic pain is primarily managed. We aimed to examine the trends, utilization characteristics, and the extent of off-label use of gabapentinoids among the US ambulatory care visits.

METHODS: This cross-sectional study used the National Ambulatory Medical Survey data from 2003-2015. Among all the adult ambulatory care visits (≥18 years), we first estimated the annual national number of visits and proportions for gabapentinoids, opioids, and benzodiazepines, respectively. We used multivariable logistic regression to test the trend significance of the annual proportion of gabapentinoid visits, adjusting for patient and prescribe characteristics. We then examined the utilization characteristics of gabapentinoid visits.

RESULTS: From 2003-2015, the visits involving gabapentinoids (7.4-30.4 million), opioids (9.9-91.3 million), and benzodiazepines (27.7-62.2 million) increased substantially. The trend of adjusted proportion of gabapentinoid visits more than tripled (9.1-33.1 per 1,000 visits; P_trend<0.0001), mainly driven by gabapentin. Among 233.1 million gabapentinoid visits from 2003-2015 (age <65 years=61.8%; female=61.9%; white=86.2%), 52.4% were from individuals having a governmental insurance and 60.3% from those with ≥2 chronic conditions. Half of the gabapentinoid visits had concurrent use with opioids (31.6%), benzodiazepines (14.9%), or both (5.8%). Nearly two-thirds of gabapentinoid visits were seen by primary care physicians (44.8%), neurology (8.4%), surgery (6.2%), and psychiatry (5.1%). Off-label use was high (gabapentin: 98.3% vs. pregabalin: 89.8%). Over 80% of gabapentinoid visits were continuous use, versus newly initiation of gabapentinoids.

CONCLUSIONS: Gabapentinoid use has increased substantially in the US ambulatory care over time. High proportions of off-label use and concurrent opioid/benzodiazepine use highlight the needs to evaluate for inappropriate gabapentinoid use.