Practice Test Geeks(PSA) Prescribing Safety Assessment Practice Test
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Drug Interactions Flashcards

6 cards from real PSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Drug Interactions flashcards as text

  1. What is a drug-drug interaction?

    Answer: When one drug affects the activity of another when both are administered together

    Drug-drug interactions occur when one medication modifies the effect of another, potentially causing increased toxicity, reduced efficacy, or unexpected adverse effects.

  2. What enzyme system is most commonly involved in drug metabolism interactions?

    Answer: Cytochrome P450 (CYP450) enzyme system

    The CYP450 system in the liver is responsible for metabolizing most drugs, and interactions involving CYP inducers or inhibitors are the most clinically significant.

  3. What happens when a CYP450 inhibitor is given with a substrate drug?

    Answer: The substrate drug level increases because its metabolism is slowed

    CYP450 inhibitors block the enzyme, reducing metabolism of the substrate drug, leading to higher blood levels and potentially increased toxicity.

  4. Why is warfarin particularly prone to drug interactions?

    Answer: It has a narrow therapeutic index, is highly protein-bound, and is metabolized by multiple CYP enzymes

    Warfarin's narrow therapeutic window means small changes in drug levels can cause serious bleeding or therapeutic failure, and many factors affect its metabolism.

  5. What is the interaction between ACE inhibitors and potassium-sparing diuretics?

    Answer: Both increase potassium levels, risking dangerous hyperkalemia

    ACE inhibitors reduce aldosterone-mediated potassium excretion, while potassium-sparing diuretics prevent potassium loss. Together they can cause dangerous hyperkalemia.

  6. What is serotonin syndrome?

    Answer: A potentially life-threatening condition caused by excessive serotonin, often from combining serotonergic drugs

    Serotonin syndrome results from excessive serotonergic activity, caused by combining drugs like SSRIs with MAOIs, tramadol, or triptans. Symptoms include agitation, hyperthermia, and clonus.