Impact of Unrestricted Access to Pregabalin on the Use of Opioids and Other CNS-Active Medications: A Cross-Sectional Time Series Analysis

Abstract

Objective: Access to pregabalin via Ontario's public drug insurance program was expanded to an unrestricted model on April 1, 2013, from a prior authorization model. This study aims to identify the effect of expanded access on the rate of pregabalin use by publicly insured persons and to assess the characteristics of new patients initiating pregabalin following this expanded access.

Methods: We conducted a cross-sectional time series analysis using the linked health administrative records of residents of Ontario, Canada, with public drug coverage who were dispensed a prescription for pregabalin between April 1, 2006, and December 31, 2014.

Results: A total of 108,047 publicly insured persons were dispensed pregabalin over the study period. The overall rate of pregabalin use increased from 1.0 per 1,000 individuals in Q1 of 2013 to 22.0 per 1,000 individuals in Q4 of 2014. Musculoskeletal (81.6%) and neurological (68.1%) conditions were the most prevalent diagnoses in patients who initiated pregabalin following the expansion of access. Past and concomitant use of opioids, nonsteroidal anti-inflammatory drugs, and antidepressants was also common in this population.

Conclusions: Formulary changes in Ontario have led to expanded access to pregabalin, which may have led to an increase in off-label use of these products and potential patient risk associated with concomitant use of pregabalin with central nervous system-depressing drugs.

Keywords: Insurance; Policy; Restricted; Unrestricted; Pregabalin.