A drug interaction is defined as a “measurable modification (in magnitude or duration) of the action of one drug by prior or concomitant administration of another substance.” This may refer to a drug-drug interaction (prescription, nonprescription, or herbal), drug-food, drug-alcohol, drug-lab test, drug-disease, or drug-chemical interactions. When we look at drug-drug interactions, they may be pharmacokinetic or pharmacodynamic in nature. This fast-paced presentation will review common examples of pharmacokinetic and pharmacodynamic drug interactions, including a brief discussion of drug interactions with medical cannabis!