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.

The trial is designed to determine whether self-titration of oxycodone and cannabis will reduce side effects in chronic pain patients with fibromyalgia. 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.