Title {1}	Cannabis-opioid interaction in the treatment of fibromyalgia pain: an open-label, proof of concept study with randomization between treatment groups: cannabis, oxycodone or cannabis/oxycodone combination – the SPIRAL study
Trial registration {2a and 2b}	EU trial register 2019–001861-33, URL https://www.clinicaltrialsregister.eu, on July 17, 2019; World Health Organization International Clinical Trials Research Platform NL7902, URL https://trialsearch.who.int, on July 26, 2019
Protocol version {3}	2.0; June 18, 2019
Funder {4}	Dutch Research Council (Nederlandse Organisatie voor Wetenschappelijk Onderzoek, NWO) in the framework of the Nationale Wetenschapsagenda—Onderzoek op Routes door Consortia Call (NWA.1160.18.300) and by Bedrocan International BV, Veendam, the Netherlands
Author details {5a}	1. Tackling and Preventing the Opioid Epidemic (TAPTOE). consortium, Utrecht, the Netherlands; 2. Department of Anesthesiology, Leiden University Medical Center, Leiden, the Netherlands; 3. Department of Clinical Pharmacy, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands; 4. Department of Pharmacology‑Toxicology and Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; 5. Department of Psychiatry, Radboud University Medical Center, Nijmegen, The Netherlands 6. Donders Center for Medical Neuroscience, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands 7. Nijmegen Institute for Scientist-Practitioners in Addiction (NISPA), Nijmegen, The Netherlands; 8. PainLess Foundation, Leiden, the Netherlands
Name and contact information for the trial sponsor {5b}	Leiden University Medical, Center, Leiden, The Netherlands; contact: a.dahan@lumc.nl
Role of sponsor {5c}	The principal investigator is the designated trial sponsor; responsible for trial design, execution, analysis and publication of outcomes. The funding parties did not influence trial design, nor will they influence data collection, data analysis, data interpretation or manuscript writing