Reductions and pronounced regional differences in morphine distribution in the United States.

Objectives: The purpose of this longitudinal study was to describe the temporal pattern of morphine distribution nationally and between states.

Methods: Drug weight was obtained from Report 5 of the US Drug Enforcement Administration's Automation of Reports and Consolidated Orders System (ARCOS) to characterize patterns in the distribution of morphine from 2012 to 2021. Morphine distribution amounts were separated by state and business type and corrected for population.