Which medications interact dangerously with CBD?

CBD is a potent inhibitor of CYP2C19 and CYP3A4 liver enzymes, and a moderate inhibitor of CYP2D6. The most clinically significant interactions: (1) Clobazam — CBD inhibits CYP2C19, increasing the active metabolite N-desmethylclobazam by 3–5x, causing sedation and respiratory depression. Dose reduction required. (2) Warfarin — CBD increases warfarin levels via CYP2C9 inhibition; INR can rise dangerously. Close monitoring required. (3) Tacrolimus and cyclosporine — immunosuppressant levels increase significantly; transplant rejection or toxicity risk. (4) Valproate — pharmacodynamic interaction causing elevated liver enzymes (additive hepatotoxicity). (5) Rifampin — a CYP inducer that dramatically reduces CBD levels. (6) Many antiepileptics, antidepressants, and antipsychotics are metabolized by these enzymes. Always consult a pharmacist before combining CBD with any prescription medication.