--Polymyxin B: Nephrotoxicity, Neurotoxicity, Apnea, Dizziness, Fever, Skin rash, Drug fever, Facial flushing, Paresthesia Chloramphenicol: Bone marrow depression, Aplastic anemia, Gray syndrome, Nausea, Vomiting, Diarrhea, Glossitis, Stomatitis, Enterocolitis, Headache, Mental confusion, Depression, Optic neuritis, Peripheral neuritis, Hypersensitivity reactions