Drug General Information (ID: DDIUELVF0B)
Drug Name			Dextropropoxyphene		Drug Info		Anisindione		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Analgesics				Anticoagulants
Structure

Mechanism of Dextropropoxyphene-Anisindione Interaction (Severity Level: Moderate)
Increased risk of bleeding Click to Show/Hide Mechanism Graph
Drug Name		Dextropropoxyphene				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 Dextropropoxyphene and Anisindione

Recommended Action
Management		Until more information is available, if propoxyphene and an anticoagulant must be used together, observation for altered anticoagulant effect is indicated. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bleeding or bruising, red or brown urine, or red or black stools.

References
1	Wells PS, Holbrook AM, Crowther NR, Hirsh J "Interactions of warfarin with drugs and food." Ann Intern Med 121 (1994): 676-83. [PMID: 7944078]
2	Jones RV "Warfarin and distalgesic interaction." Br Med J 1 (1976): 460
3	Orme M, Breckenridge A, Cook P "Warfarin and distalgesic interaction." Br Med J 1 (1976): 200