Reddit posts revealed unreported drug interactions between cannabis products and immunosuppressants

Searching 63.5 million Reddit posts, researchers identified 190 posts discussing both cannabis-derived products (CDPs) and immunosuppressants. Of these, 66 posts (35%) expressed concern about potential drug-drug interactions, and 4 posts (2%) reported actual adverse interactions. Two of the four matched the known CBD/tacrolimus interaction discovered in Epidiolex trials. Two others reported previously undocumented interactions: a CBD or THC/sirolimus interaction and a THC/tacrolimus interaction, both resulting in drug toxicity.

Searched Reddit for subreddits related to cannabis-derived products or health, yielding 63,561,233 posts. Identified 190 posts discussing both immunosuppressants and CDPs. Two blinded investigators evaluated posts for DDI concerns and reported adverse events.

Consumer cannabis products are unregulated and cannot be tested in clinical trials the way Epidiolex was. This study demonstrates that real-world drug interactions are occurring with consumer CBD and THC products and going unreported to formal pharmacovigilance systems, creating a hidden safety gap.

As cannabis legalization expands while millions of Americans take immunosuppressants for organ transplants, autoimmune diseases, and cancer, the interaction risk grows. Traditional pharmacovigilance misses these events because consumer cannabis products exist outside the regulated pharmaceutical system.

Social media data cannot verify clinical outcomes or confirm causation. Four reported DDI events is a very small number from which to draw conclusions. Reddit users may not accurately describe medications, doses, or outcomes. Cannot estimate the true incidence of these interactions.