Drug Interaction Checker
Check interactions between concurrently prescribed medications
Medication List to Check
Warfarin ↔ Aspirin
Concurrent use significantly increases bleeding risk.
Mechanism: Both have anticoagulant/antiplatelet effects. Aspirin also displaces warfarin from protein binding.
Management: Avoid combination unless benefit clearly outweighs risk. If concurrent use necessary, monitor INR closely and watch for bleeding signs.
Metformin ↔ IV Contrast Dye
Risk of lactic acidosis — potentially fatal if metformin not held before contrast.
Mechanism: Contrast agents can cause acute kidney injury; reduced renal function leads to metformin accumulation and lactic acidosis.
Management: Hold metformin 48h before and 48h after IV contrast. Restart only when renal function confirmed stable.
Ciprofloxacin ↔ Warfarin
Fluoroquinolones inhibit CYP1A2 and CYP3A4 — significantly increases warfarin effect and INR.
Mechanism: CYP enzyme inhibition reduces warfarin metabolism; also displaces warfarin from albumin.
Management: Monitor INR closely after starting or stopping ciprofloxacin. Reduce warfarin dose preemptively if INR typically stable.