Madam, Ferralet 90 is not an antibiotic it is a combination of Iron, Vit c, B12 & Folic acid. It has no side effects for breast feeding your baby. But the doctor must have given you one antibiotic also. You can t miss that. How is the abscess now? You must be having fever also. Any pus oozing out? Tell me the other medicines for fever & bodyache you are prescribed.