ABSTRACT The increasing utilization of cannabis products combined with lack of data regarding potential cannabis–prescription drug interactions is concerning. This study aimed to review published case reports and FDA Adverse Event Reporting System (FAERS) spontaneous reports to assess cannabis–drug interactions in persons aged 18 and over. A literature search identified 20 case reports that were each assessed for drug interaction causality using the Drug Interaction Probability Scale. Data collected from the FAERS revealed a greater proportion of reports mentioning serious outcomes, including death, when cannabis was used concomitantly with controlled substances compared to noncontrolled substances. Fisher's exact test showed a statistically significant difference between...