Effects of Opioid Overdose Prevention Laws on Pharmaceutical Detailing and Physician Prescribing

Abstract

Expanding access to naloxone has been identified as a critical strategy in fighting the American opioid crisis. Between 2014 and 2021, fourteen states passed naloxone co-prescribing laws which require physicians to prescribe naloxone to patients alongside opioid medications. This paper is the first to analyze the effects of state naloxone laws on opioid-related outcomes for physicians and pharmaceutical firms. Using physician-level CMS Open Payments and CMS Medicare Part D Prescribers data, this study constructs several difference-in-differences and instrumental variable models to estimate the causal effects of a naloxone co-prescribing law on pharmaceutical direct-to-physician marketing, also known as detailing, and physician prescribing of opioids. Empirical results show that a naloxone law has large negative effects on both opioid detailing and prescribing at the physician level but that these effects dissipate between two to three years after the policy is introduced. There is also significant heterogeneity in these effects across physician and market characteristics including historical prescribing volume, specialty, and geography. In order to account for the downstream impact of detailing payments on physician prescribing rates, the effect on prescribing is further deconstructed into negative direct and indirect effects. These results suggest that a state naloxone access law may have temporary positive spillover effects on the opioid epidemic through lowering prescription opioid use.