Recreational Cannabis Laws Were Linked to Reduced Codeine Dispensing Across US Pharmacies | Research

The takeaway

States that adopted recreational cannabis laws saw a reduction in codeine dispensed at retail pharmacies, with codeine being the opioid most likely to be used non-medically.

Public health officials, drug policy researchers, legislators evaluating cannabis legalization.

Recreational cannabis laws reduced codeine dispensing but not other opioids

What the researchers found

Using two-way fixed-effects regressions across 11 states that adopted recreational cannabis laws between 2010 and 2019, the study found RCLs led to a reduction in codeine dispensed at retail pharmacies. No significant effects were found for other opioid types. The analysis accounted for opioid prescribing limits and other policies.

Why it matters

Unlike prior studies that examined prescriptions from specific payers, this study captured all retail pharmacy dispensing. The finding that codeine, the opioid most associated with non-medical use, specifically declined suggests cannabis may substitute for recreational or quasi-medical opioid use.

The numbers in context

11 US states with RCLs adopted 2010-2019. Significant reduction in codeine dispensing. No significant effects on other opioid types. Adjusted for opioid prescribing limits.

How the study worked

Two-way fixed-effects regression using variation from 11 US states that adopted recreational cannabis laws between 2010 and 2019, examining dispensing data across all payers and endpoints.

What this study cannot tell us

Observational policy analysis cannot confirm causation. Cannot distinguish between recreational and medical substitution. State-level data may mask variation within states. Time period may not capture long-term effects.

How to read the evidence

Policy analysis using robust two-way fixed-effects models across 11 states, adjusted for competing opioid policies.

When this study was published

Published in 2023 using data from 2010-2019.

The bigger picture

The specificity of the codeine finding is telling. Codeine is often used for mild pain and is the most accessible prescription opioid for non-medical use. That cannabis appears to substitute specifically for codeine rather than stronger opioids suggests the substitution effect may be strongest where the clinical need is lowest.

Questions still open

Does the codeine reduction reflect less recreational misuse or less medical prescribing?
Will the substitution effect extend to stronger opioids over time?

Common questions

Do recreational cannabis laws reduce opioid use?

This study found they reduced codeine dispensing specifically. Codeine is the prescription opioid most associated with non-medical use. Other opioid types were not significantly affected.

Why only codeine?

The authors suggest cannabis may substitute for opioids used non-medically or for mild pain, which aligns with codeine being the most accessible and mildly potent prescription opioid.

Read the original research

Recreational cannabis and opioid distribution.

Health economics, 32(4), 747-754

View on PubMed ↗Publisher’s paper ↗

Citation

Raman, Shyam; Maclean, Johanna Catherine; Bradford, W David; Drake, Coleman. (2023). Recreational cannabis and opioid distribution.. Health economics, 32(4), 747-754. https://doi.org/10.1002/hec.4652