Your patient has taken Warfarin without any trouble for years. He is being seen today for a large hematoma on his leg.

Your patient has taken Warfarin without any trouble for years. He is being seen today for a large hematoma on his leg. He says he just “brushed” the coffee table this morning. You take a complete medication history and find that he began taking Pepto-Bismol; for a GI “bug” for 3 days ago. You suspect that the ASA in the Pepto-Bismol o Displaced the Warfarin from the plasma proteins, causing increased free drug o Altered the gastric pH, causing an increase in Warfarin absorption o Acified the urine, causing less Warfarin to be excreted by the kidneys o Bound to a site near the Warfarin receptor and acted as a Warfarin antagonist