Compounded Decoquinate / Levamisole HCL Oral Suspension from PetScript Pharmacy is available at Decoquinate 7.6mg/ml & Levamisole HCL 30mg/ml. Compounded Decoquinate Levamisole/ is frequently prescribed to treat symptoms of Equine Protozoal Myeloencephalitis (EPM), a severe neurological disorder in horses caused by Sarcocystis neurona. This medication is often used for horses that have not responded to other treatments.