Italian safety reports highlight risks of medical cannabis use

Several European countries allow the use of galenic cannabis preparations as second line treatment especially for analgesia in chronic pain. Currently, there is a lack of information on the safety of cannabis use. The aim of this study is to provide data useful for improving knowledge on the cannabis safety for medical purpose. Spontaneous reports of adverse reactions (ARs) referred to medical cannabis preparations are gathered within the Italian Phytovigilance System since 2015. Diagnoses were coded through the Medical Dictionary for Regulatory Activities. We extrapolated data from 30 November 2015 to 30 June 2024, and all clinical and pharmacological characteristics of cases were analysed. Causality assessment was performed using an evaluation scale adapted from the World Health Organization. During the study period, 210 reports related to medical cannabis preparations were collected in Italy, with a peak of 24% in 2019. Most reports came from healthcare professionals, with females experiencing ARs three times more than males. The most common ARs were neurological/psychotic issues (47.1%), gastrointestinal reactions (15.5%) and cardiovascular problems (7.4%). Serious ARs accounted for 21.2%, and concomitant drugs or conditions were often involved in ARs. Data show that females experienced ARs more than males, potentially due to biological differences, prescription practices or consumption patterns. The study notes the importance of monitoring pharmacological interactions, especially with benzodiazepines, which may affect cannabis metabolism. Although spontaneous reporting systems have limitations, they provide valuable insights into the safety profile of cannabis. Further studies are needed for better prescription practices and risk management.