Drug Interactions Pharmacology: A Narrative Review

Abstract

The simultaneous prescription of multiple drugs used in therapeutic schemes can result in drug interactions, with desirable or undesirable effects. Thus, the objective of this study was to describe the mechanisms involved in clinically relevant drug interactions. This is a narrative review in which studies published in PUBMED and the VHL were searched in the following databases: MedLine, Lilacs, and Scielo. The search was performed in May 2021, after reading the articles and their references. The results showed that drug interactions occur through the co-administration of different compounds. In this context, drugs can suffer pharmaceutical interactions due to different physical-chemical processes, as well as after administration, interfering in the mechanisms of absorption, distribution, metabolism, and elimination of pharmacokinetics or pharmacodynamics, with changes in the pharmacological effect. Such mechanisms can cause undesirable outcomes, such as increased toxicity or impairment of therapeutic effect, or be used as a strategy for beneficial interactions to increase the pharmacological effect or reduce toxicity. Given the clinical impacts that may occur due to drug interactions, knowledge about the different mechanisms involved in drug interactions is essential.