Medical Cannabis Did Not Cause Liver Enzyme Elevations in Cancer Patients

No patients in the cannabis groups exceeded predefined safety thresholds (3x upper limit of normal for ALT or AST, or 5x for those with liver metastases). No clinically meaningful differences in liver enzyme levels were observed between CBD-only and THC/CBD combination products or compared with placebo.

Substudy of two multicentre, randomized, placebo-controlled trials (MedCan1: CBD alone; MedCan2: THC/CBD) in 287 patients with advanced cancer. Liver enzymes (ALT, AST) measured at baseline, day 14, and day 28 with escalating doses up to 600 mg CBD/day.

Liver safety is a known concern with pharmaceutical CBD (Epidiolex carries a liver enzyme warning). This RCT-derived safety data in a vulnerable cancer population provides reassurance that medicinal cannabis at moderate doses does not appear to cause hepatotoxicity over one month.

Cancer patients often have compromised liver function from chemotherapy, metastases, or both. Demonstrating that medicinal cannabis does not add to hepatic burden at therapeutic doses strengthens the case for its use in palliative care, where quality of life is the primary concern.

Only 28 days of follow-up; longer-term effects unknown. Maximum dose of 600 mg CBD/day is lower than some clinical protocols. Patients with severely impaired liver function may have been excluded from the original trials. Substudy analysis was not the primary endpoint of either trial.