Problem medications for dogs

March 1, 2022

Learn what medications may be dangerous for your dog with the MDRI genetic mutation.

Dogs with the MDR1 genetic mutation can become very ill or die if given certain medications. WSU is the leader in identifying drugs that may be dangerous for dogs with the MDR1 mutation and can identify alternative medications and doses.

Once WSU has determined your dog’s MDR1 status, board- certified veterinary pharmacologist Dr. Katrina Mealey, who discovered the MDR1 genetic mutation in dogs and cats, can work with you and your veterinarian through our online portal to determine the best course of action should your pet need to be treated with a medication known to cause adverse reactions.

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Drug (Active Ingredient)	Brand Name	Recommendation
Acepromazine		Contact PrIMe for dosing recommendations
Afoxolaner	Nexgard	The manufacturer of Nexgard has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. Dogs with the MDR1 mutation are not at increased risk for adverse effects.
Apomorphine		Contact PrIMe for dosing recommendations
Butorphanol	Torbugesic	Contact PrIMe for dosing recommendations
Chemotherapy		Contact PrIMe for dosing recommendations
Cyclosporine	Atopica	Contact PrIMe for dosing recommendations
Doxorubicin		See Chemotherapy
Fluralaner	Bravecto	The manufacturer of Bravecto has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. Dogs with the MDR1 mutation are not at increased risk for adverse effects.
Grapiprant	Galliprant	Contact PrIMe for dosing recommendations
ivermectin	Heartgard	The manufacturer of Heartgard has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. The FDA determined Heartgard is safe for dogs with the MDR1 mutation when used at label doses. For other formulations of ivermectin Contact PrIMe for dosing recommendations.
Loperamide	Imodium	At doses used to treat diarrhea, this drug will cause neurological toxicity in dogs with the MDR1 mutation. This drug should be avoided in all dogs with the MDR1 mutation.
Milbemycin	Interceptor	The manufacturer of Interceptor has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. The FDA determined Interceptor is safe for dogs with the MDR1 mutation when used at label doses. For other formulations of milbemycin Contact PrIMe for dosing recommendations.
Maropitant	Cerenia	Contact PrIMe for dosing recommendations
Moxidectin	ProHeart	The manufacturer of ProHeart has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. The FDA determined ProHeart is safe for dogs with the MDR1 mutation when used at label doses.
Ondansetron		Contact PrIMe for dosing recommendations
Sarolaner	Simparica	The manufacturer of Simparica has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. Dogs with the MDR1 mutation are not at increased risk for adverse effects.
Vinblastine		See Chemotherapy
Vincristine		See Chemotherapy
Vinorelbine		See Chemotherapy
Selamectin	Revolution	The manufacturer of Revolution has tested the product for safety in dogs with the MDR1 mutation. No adverse effects were observed. The FDA determined Revolution is safe for dogs with the MDR1 mutation when used at label doses.

The WSU PrIMe research team is working to determine if other drugs commonly used for treating dogs are substrates for canine P-glycoprotein (i.e., have the potential to cause toxicity in dogs with the MDR1 mutation).

Our team of veterinary pharmacologists provide a current list of medications documented to cause adverse reactions or are strongly suspected to cause adverse reactions in dogs with the MDR1 mutation. Research efforts are underway to determine if new veterinary and human drug products could be problematic for dogs with the MDR1 mutation.