Drug interaction refers to the effects that occur when two or more drugs are taken together, potentially altering the way one or both drugs work in the body. This can occur when drugs interact with each other to enhance or reduce their effects, or when one drug affects the way another drug is metabolized by the body. Drug interactions can lead to adverse reactions, reduced effectiveness of medications, or new and unexpected side effects. It is important for healthcare providers to be aware of potential drug interactions when prescribing multiple medications to a patient to ensure the safety and efficacy of their treatment.