Drug interaction

Also known as: DDI, drug-drug interaction

A change in a drug's effect or safety caused by co-administration with another drug.

Definition

A drug-drug interaction (DDI) occurs when one drug alters the pharmacokinetics or pharmacodynamics of another, changing efficacy or toxicity. Major mechanisms: CYP450 enzyme induction/inhibition, transporter modulation (P-gp, OATP), and additive pharmacology. Clinically significant DDIs are listed in FDA labels and Lexicomp.

See also

Other safety terms