Drug General Information (ID: DDI329PAWN)
  Drug Name Quinidine Drug Info Anisindione Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Group I Antiarrhythmics Anticoagulants
  Structure

 Mechanism of Quinidine-Anisindione Interaction (Severity Level: Moderate)
     Increased risk of bleeding Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Quinidine Anisindione
      Mechanism Potentiate the hypoprothrombinemic effect of vitamin K antagonist Vitamin K antagonist
      Key Mechanism Factor 1
Factor Name Bleeding
Factor Description Patients may be at risk for bleeding when the outcome of a disease or disease treatment confounds the standard mechanisms for maintaining hemostasis. Signs or symptoms of abnormal bleeding include: bleeding that takes a long time to stop (including nosebleeds, bleeding gums, bleeding from cuts and abrasions, and menstrual bleeding); severe unexplained bruising, or bruising that becomes larger; blood in the urine or stool, etc.
      Mechanism Description
  • Increased risk of bleeding by the combination of Quinidine and Anisindione 

Recommended Action
      Management INR should be monitored, and the dosage of oral anticoagulant adjusted as needed. Patients should be advised to notify their physicians if they experience any signs of excessive anticoagulation, such as unusual or prolonged bleeding, bruising, vomiting, change in stool or urine color, headache, dizziness, or weakness.

References
1 Koch-Weser J, Sellers EM "Drug interactions with coumarin anticoagulants (second of two parts)." N Engl J Med 285 (1971): 547-58. [PMID: 4397794]
2 Ku LL, Ward CO, Durgin SJ "A clinical study of drug interaction and anticoagulant therapy." Drug Intell Clin Pharm 4 (1970): 300-6.
3 Koch-Weser J "Quinidine-induced hypoprothrombinemic hemorrhage in patients on chronic warfarin therapy." Ann Intern Med 68 (1968): 511-7