Drug Interactions By Shalini S Lynch, PharmD, University of California San Francisco School of Pharmacy Reviewed / Revised Jul 2022 | Modified Sep 2022 View Patient Education Topic Resources Some Drugs With Potentially... Drug interactions are changes in a drug's effects due to recent or concurrent use of another drug or drugs (drug-drug interactions), ingestion of food (drug-nutrient interactions), or ingestion of dietary supplements (dietary supplement-drug interactions).