title: Phytonadione therapy in a multiple-drug overdose involving warfarin.
abstract: We cared for a patient who ingested an unknown amount of acetaminophen with zopiclone and warfarin. The only liver function test that was abnormal was an increased international normalized ratio (INR), which remained elevated despite treatment with subcutaneous phytonadione and a prolonged infusion of N-acetylcysteine. An interaction between acetaminophen and warfarin may have decreased the hepatic metabolism of warfarin. The patient received numerous antibiotics that may have contributed to the increased INR. The prolonged elevation of INR also may have been due to infrequent administration of phytonadione.
authors.affiliation: Foothills Medical Centre, Calgary, Alberta, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Bates
authors.forename: M
authors.initials: M
authors.lastname: Mintz
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects; D000111:Acetylcysteine / Q000627:therapeutic use*; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects* / Q000493:pharmacokinetics; D000931:Antidotes / Q000627:therapeutic use*; D000933:Antifibrinolytic Agents / Q000627:therapeutic use; D053961:Azabicyclo Compounds; D002606:Charcoal / Q000627:therapeutic use*; D004347:Drug Interactions; D062787:Drug Overdose / Q000188:drug therapy; D005260:Female; D005751:Gastric Lavage; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects; D019934:International Normalized Ratio; D010879:Piperazines / Q000009:adverse effects; D014812:Vitamin K / Q000493:pharmacokinetics*; D010837:Vitamin K 1 / Q000627:therapeutic use*; D014859:Warfarin / Q000009:adverse effects* / Q000493:pharmacokinetics
chemical_list: D018712:Analgesics, Non-Narcotic; D000900:Anti-Bacterial Agents; D000925:Anticoagulants; D000931:Antidotes; D000933:Antifibrinolytic Agents; D053961:Azabicyclo Compounds; D006993:Hypnotics and Sedatives; D010879:Piperazines; C515050:zopiclone; D014812:Vitamin K; D002606:Charcoal; D000082:Acetaminophen; D014859:Warfarin; D010837:Vitamin K 1; D000111:Acetylcysteine