Although moxidectin is in the same drug family as ivermectin, some veterinarians use it, combined with imidacloprid (Advantage Multi ®) to treat mange successfully — even in dogs with the MDR1 aka ABCB1 gene mutation. (2ndchance.info)
Washington State U. Vet School says, re ivermectin: «While the dose of ivermectin used to prevent heartworm infection (6 micrograms per kilogram) is safe in dogs with the [MDR1] mutation, higher doses such as those used for treating mange (300 - 600 micrograms per kilogram)[are not].» (thedogplace.org)
Can I use an anti-itch shampoo to help him with the itching as well as his medicine treating the mange (1800petmeds.com)