This page holds the [study protocol](https://osf.io/4fu7b), data, code and results for our study published [here in the British Journal of Clinical Pharmacology](https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bcp.14786), which systematically searched and synthesized secondary data sources to create a list of opioid drugs and a centralised repository entitled the [Oxford Catalogue of Opioids](https://www.catalogueofopioids.net/) that will share information to assist researchers, prescribers, and the public to improve the safe use of opioids.