CYP2C9 and cancer: In another cross-sectional survey by Saadeh et al. [143] on medical marijuana use across varying cancer stages, drug interactions were reported with sympathomimetic agents, cytochrome P450 (CYP) isoform 1A2 substrates, CYP2C9 inhibitors and anticholinergic agents, with the highest occurrence noted with CNS depressants.