Drug General Information (ID: DDIEY074F8)
Drug Name			Valganciclovir		Drug Info		Avapritinib		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiviral Agents				Multikinase Inhibitors
Structure

Mechanism of Valganciclovir-Avapritinib Interaction (Severity Level: Moderate)
Additive myelosuppressive effects Click to Show/Hide Mechanism Graph
Drug Name		Valganciclovir				Avapritinib
Mechanism 1		Myelosuppressive effects				Myelosuppressive effects
Key Mechanism Factor 1
		Factor Name		Myelosuppressive effects
		Factor Description		Myelosuppression, also known as bone marrow suppression, is a decrease in bone marrow activity that leads to a decrease in the production of blood cells. Some blood cell disorders include: erythrocytopenia (anemia), leukopenia (neutropenia), and thrombocytopenia (thrombocytopenia).
Mechanism Description		Additive myelosuppressive effects by the combination of Valganciclovir and Avapritinib
Increased risk of nephrotoxicity Click to Show/Hide Mechanism Graph
Drug Name		Valganciclovir				Avapritinib
Mechanism 2		Nephrotoxicity				Nephrotoxicity
Key Mechanism Factor 2
		Factor Name		Nephrotoxicity
		Factor Description		The combination of drugs that can induce nephrotoxicity may increase the risk of kidney injury. When kidney injury occurs, the inability to remove excess urine and waste from the body can lead to high levels of urea nitrogen, creatinine, and electrolytes (such as potassium and magnesium) in the blood.
Mechanism Description		Increased risk of nephrotoxicity by the combination of Valganciclovir and Avapritinib

Recommended Action
Management		Ganciclovir or its prodrug, valganciclovir, should generally not be combined with other drugs associated with myelosuppression and/or nephrotoxicity unless the benefits are anticipated to outweigh the potential risks. Extreme caution is advised if they are used in patients who have recently received or are receiving treatment with myelotoxic and/or nephrotoxic drugs, and vice versa. If coadministration is required, reduced dosages of one or more of the drugs may be required, and the patient should be monitored for the development of hematologic and/or renal adverse effects both during and after discontinuation of therapy.

References
1	Cerner Multum, Inc. "Australian Product Information.".
2	Cerner Multum, Inc. "UK Summary of Product Characteristics.".
3	Product Information. Cytovene (ganciclovir). Genentech, South San Francisco, CA.
4	Product Information. Valcyte (valganciclovir) Roche Laboratories, Nutley, NJ.