ABSTRACT
Overdoses of macrocyclic lactones in dogs and cats can result in such signs as tremors, ataxia, seizures, coma, and blindness. Dogs with the ABCB1-1Δ gene defect are predisposed to macrocyclic lactone toxicosis at lower dosages than dogs without the defect. Intravenous lipid emulsion therapy has been suggested for treatment of macrocyclic lactone toxicosis but evidence of efficacy is limited. Initial decontamination and supportive care remain the mainstays of therapy for macrocyclic lactone toxicosis.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/pharmacology , Anthelmintics/toxicity , Cat Diseases/chemically induced , Dog Diseases/chemically induced , Ivermectin/analogs & derivatives , Macrolides/toxicity , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Animals , Cat Diseases/genetics , Cat Diseases/therapy , Cats , Dog Diseases/genetics , Dog Diseases/therapy , Dogs , Fat Emulsions, Intravenous/therapeutic use , Genotype , Ivermectin/pharmacokinetics , Ivermectin/toxicity , Lactones , Macrolides/pharmacokinetics , Seizures/chemically induced , Seizures/therapy , Seizures/veterinaryABSTRACT
The macrocyclic lactones (MLs) are parasiticides able to kill a wide variety of arthropods and nematodes. They have a high margin of safety for labeled indications, and ivermectin has become the best-selling antiparasitic in the world. Dogs of certain breeds and mixtures of those breeds have a defect in the ABCB1 gene (formerly MDR1 gene) that results in a lack of functional P-glycoprotein, which leads to accumulation of the MLs in the central nervous system and a higher risk of adverse effects when exposed. There is no specific antidote for ML toxicosis so the most important part of treatment is good supportive care.