Problem medications for dogs

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.

Drug (Active Ingredient)Brand NameRecommendation
AcepromazineContact PrIMe for dosing recommendations
AfoxolanerNexgardThe 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.
ApomorphineContact PrIMe for dosing recommendations
ButorphanolTorbugesicContact PrIMe for dosing recommendations
ChemotherapyContact PrIMe for dosing recommendations
CyclosporineAtopica
Contact PrIMe for dosing recommendations
DoxorubicinSee Chemotherapy
FluralanerBravectoThe 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.
GrapiprantGalliprantContact PrIMe for dosing recommendations
ivermectinHeartgardThe 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.
LoperamideImodiumAt 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.
MilbemycinInterceptor 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.
MaropitantCereniaContact PrIMe for dosing recommendations
MoxidectinProHeartThe 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.
OndansetronContact PrIMe for dosing recommendations
SarolanerSimparicaThe 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.
VinblastineSee Chemotherapy
VincristineSee Chemotherapy
VinorelbineSee Chemotherapy
SelamectinRevolutionThe 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.