What is a drug-drug interaction?

A drug-drug interaction is specifically defined as a reaction that occurs when two or more drugs are administered simultaneously, affecting how each medication works in the body. This can happen in various ways, such as altering the effectiveness, increasing the toxicity, or modifying the side effects of one or more of the involved drugs. These interactions can lead to unexpected outcomes, complicating treatment plans and potentially putting patients at risk.

While other concepts might involve drug interactions, such as cumulative effects or enhancement of side effects, the primary focus in this context is the concurrent administration of different medications and the resulting reactions. Additionally, it's worth noting that although drug interactions can involve metabolic processes in the liver, this is only one aspect of how drugs can affect each other and does not encompass the broader definition of drug-drug interactions.