Drug Interactions Flashcards
6 cards from real Pharmacy 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
A patient on warfarin starts taking aspirin. What is the primary concern?
Answer: Increased risk of bleeding
Aspirin inhibits platelet aggregation and may displace warfarin from protein binding sites, significantly increasing bleeding risk when combined.
Which drug, when combined with an SSRI, can cause serotonin syndrome?
Answer: Tramadol
Tramadol inhibits serotonin reuptake; combining it with SSRIs can lead to excessive serotonin accumulation, causing serotonin syndrome.
Grapefruit juice is known to inhibit which enzyme, causing elevated plasma levels of many drugs?
Answer: CYP3A4
Grapefruit juice inhibits intestinal CYP3A4, reducing first-pass metabolism of many drugs (e.g., statins, calcium channel blockers), increasing their plasma concentrations.
Concurrent use of an ACE inhibitor and a potassium-sparing diuretic increases the risk of:
Answer: Hyperkalemia
Both ACE inhibitors (reduce aldosterone) and potassium-sparing diuretics (block aldosterone or sodium channels) retain potassium, leading to dangerous hyperkalemia.
Ciprofloxacin should not be taken within 2 hours of antacids containing aluminum or magnesium because:
Answer: Cations chelate ciprofloxacin, reducing absorption
Divalent and trivalent cations (Al³⁺, Mg²⁺, Ca²⁺, Fe²⁺, Zn²⁺) chelate fluoroquinolones, forming insoluble complexes that dramatically reduce oral absorption.
What type of drug interaction occurs when two drugs with similar CNS depressant effects are combined?
Answer: Additive/synergistic effect
Combining CNS depressants (e.g., opioids + benzodiazepines) produces additive or synergistic sedation, respiratory depression, and increased risk of overdose.