Tetrahydrocannabinol (THC) in patients with fibromyalgia syndrome (FMS). A retrospective study of changes in pain, psychometric variables, and analgesic consumption during inpatient interdisciplinary multimodal pain therapy (IMPT)

Background: SinceMarch 1, 2017, medical cannabis (MC) can be prescribed nationwide in Germany. To date, there have been a number of qualitatively different studies on the effectiveness of MC in fibromyalgia syndrome (FMS). Objective: The aim of the studywas to investigate the effectiveness of THC in the course of interdisciplinary multimodal pain therapy (IMPT) on pain and several psychometric variables. Materials and methods: For the study, in the period 2017-2018, all patients in the pain ward of a clinic who were suffering from FMS and were treated in a multimodal interdisciplinary setting were selected based on inclusion criteria. The patients were examined separately according to groups with and without THC about pain intensity, various psychometric parameters and analgesic consumption during the stay. Results: Of the 120 FMS patients included in the study, 62 patients (51.7%) were treated with THC. In the parameters of pain intensity, depression, and quality of life, there was a significant improvement in the entire group during the stay (p < 0.001), which was significantly greater through the use of THC. In five of the seven analgesic groups examined, the dose was reduced or the drug discontinued significantly more often in the patients treated with THC. Conclusion: The results provide indications that THC can be considered as a medical alternative in addition to the substances previously recommended in various guidelines.