Drug interactions

Drug–drug interactions (DDIs) arise when the effects of one drug are altered by the co-administration of another. The clinical response depends on many factors, including individual patient characteristics such as age, co-morbidities and pharmacogenetics. The number of potential DDIs is extensive but most have minimal impact on patient outcomes. DDIs are classified as pharmacokinetic-related, where drug absorption, distribution, metabolism or excretion are affected, or pharmacodynamic-related, when drugs with similar pharmacological actions are co-prescribed.