Problem medications for cats

Since the feline MDR1 mutation was more recently discovered than the canine MDR1 mutation there has been less research on the topic. The WSU PrIMe research team is working to determine if other drugs commonly used for treating cats are substrates for feline P-glycoprotein (i.e., have the potential to cause toxicity in cats with the MDR1 mutation).

Drug (Active Ingredient)Brand NameRecommendation
ChemotherapyContact PrIMe for dosing recommendations
EmodepsideDo not use in cats with the MDR1 mutation
EprinomectinDo not use in cats with the MDR1 mutation
IvermectinHeartgardIf used in accordance with label, the dose of ivermectin is low enough to be safe for cats with the MDR1 mutation.
For other formulations of ivermectin contact Contact PrIMe for dosing recommendations
LoperamideImodiumAt doses used to treat diarrhea, this drug will would be expected to cause neurological toxicity in cats with the MDR1 mutation. We recommend avoiding loperamide in cats with the MDR1 mutation.
MilbemycinInterceptor
If used in accordance with label, the dose of milbemycin is low enough to be safe for cats with the MDR1 mutation.
For other formulations of milbemycin
Contact PrIMe for dosing recommendations
MoxidectinAdvantage MultiOral ingestion of this topical product would be expected to cause neurological toxicity in cats with the MDR1 mutation.
VinblastineSee Chemotherapy
VincristineSee Chemotherapy
VinorelbineSee Chemotherapy
SelamectinRevolutionOral ingestion of this topical product would be expected to cause neurological toxicity in cats with the MDR1 mutation.