Drug General Information (ID: DDIXNRJ8VD)
Drug Name			Isotretinoin		Drug Info		Anisindione		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiacne Agents/Antineoplastics				Anticoagulants
Structure

Mechanism of Isotretinoin-Anisindione Interaction (Severity Level: Moderate)
Antagonize the effect of antithrombotic agents Click to Show/Hide Mechanism Graph
Drug Name		Isotretinoin				Anisindione
Mechanism		Decrease the hypoprothrombinemic effect of vitamin K antagonist				Vitamin K antagonist
Key Mechanism Factor 1
		Factor Name		Antithrombotic agents
		Factor Description		The beneficial effects of antithrombotic agents are reduced, leading to an increased risk of thromboembolism, stroke and/or myocardial infarction.
Mechanism Description		Antagonize the effect of Anisindione when combined with Isotretinoin

Recommended Action
Management		Until further information is available, INR should be monitored more closely whenever isotretinoin is added to or withdrawn from therapy, and the warfarin dosage adjusted as necessary. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking.

References
1	Bodiford AB, Kessler FO, Fermo JD, Ragucci KR "Elevated international normalized ratio with the consumption of grapefruit and use of warfarin." SAGE Open Med Case Rep 0 (2013): 1-3. [PMID: 27489634]
2	Guo LQ, Yamazoe Y "Inhibition of cytochrome P450 by furanocoumarins in grapefruit juice and herbal medicines." Acta Pharmacol Sin 25 (2004): 129-36. [PMID: 14769198]
3	Fiallo P "Reduced therapeutic activity of warfarin during treatment with oral isotretinoin." Br J Dermatol 150 (2004): 164