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Intermediate Technical IVT

drug-drug interaction

When one medication affects the activity of another when taken concurrently.

Full Definition

A pharmacological phenomenon where one medication alters the pharmacokinetics or pharmacodynamics of another medication when administered simultaneously. In psychopharmacology, drug-drug interactions are particularly important due to the complex enzyme systems involved in psychiatric medication metabolism and the potential for serious adverse effects like serotonin syndrome. Interactions can be pharmacokinetic (affecting absorption, distribution, metabolism, or elimination) or pharmacodynamic (affecting the medication's action at its target site). Understanding these interactions is crucial for safe prescribing and medication management.

Usage

Usage note: Usually hyphenated to distinguish from other types of interactions. May be abbreviated as DDI in clinical notes.

In Context

  • "The drug-drug interaction between fluoxetine and tamoxifen reduces the anticancer medication's effectiveness." — Clinical pharmacology review
  • "Comprehensive drug-drug interaction screening prevented a potentially serious adverse event." — Quality improvement report

Also known as

DDI medication interaction

Don't confuse with

drug-food interaction drug-disease interaction

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