State-specific naloxone related legislation is available from Prescription Drug Abuse Policy System (PDAPS) which is a NIDA resource that also has maps and data on Prescription Drug Monitoring Program and Good Samaritan 911 Laws.
This in-depth explanation of legal interventions to reduce overdose mortality was compiled by the Network for Public Health Law. There are also select state-specific reports:
Legal changes to increase access to naloxone for opioid overdose reversal in the United States
Corey Davis & Derek Carr, Drug and Alcohol Dependence, 2015
Naloxone for Community Opioid Overdose Reversal
Corey Davis, Public Health Law Research, 2015