Drug General Information (ID: DDIWYT78CO)
Drug Name			Warfarin		Drug Info		Orlistat		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Anticoagulants				Antiobesity Agents
Structure

Mechanism of Warfarin-Orlistat Interaction (Severity Level: Moderate)
Altered absorption (Unspecific) Click to Show/Hide Mechanism Graph
Drug Name		Warfarin				Orlistat
Mechanism		Absorption possibly altered by orlistat				Orlistat
Key Mechanism Factor 1
		Factor Name		Pharmacokinetic
		Factor Description		Alters the absorption of the drug, leading to changes in the plasma concentration of the drug and affecting the pharmacological effects.
Mechanism Description		Altered absorption of Warfarin caused by Orlistat

Recommended Action
Management		Patients should be closely monitored during concomitant therapy with oral anticoagulants and orlistat. The INR should be checked frequently and anticoagulant dosage adjusted accordingly, particularly following initiation or discontinuation of orlistat in patients who are stabilized on their anticoagulant regimen. 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	MacWalter RS, Fraser HW, Armstrong KM "Orlistat enhances warfarin effect." Ann Pharmacother 37 (2003): 510-2. [PMID: 12659605]
2	Product Information. Xenical (orlistat). Roche Laboratories, Nutley, NJ.