Drug General Information (ID: DDIS6B5E83)
Drug Name			Valproic acid		Drug Info		Vorinostat		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Anticonvulsants				Antineoplastics
Structure

Mechanism of Valproic acid-Vorinostat Interaction (Severity Level: Major)
Increased risk of bleeding Click to Show/Hide Mechanism Graph
Drug Name		Valproic acid				Vorinostat
Mechanism		Risk of bleeding Antiplatelet effects				Risk of bleeding Antiplatelet effects
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 Valproic acid and Vorinostat

Recommended Action
Management		Blood cell counts, including platelets, should be performed every two weeks during the first two months of vorinostat therapy, then monthly thereafter. If abnormalities develop, the dosage should be reduced or therapy discontinued.

References
1	Gilman AG, Rall TW, Nies AS, Taylor P, eds. "Goodman and Gilman's the Pharmacological Basis of Therapeutics. 8th ed." New York, NY: Pergamon Press Inc. (1990):.
2	Product Information. Fycompa (perampanel). Eisai Inc, Teaneck, NJ.
3	Product Information. Zolinza (vorinostat). Merck &amp Company Inc, West Point, PA.