Erythromycin, Generic Erythromycin, Erythromycin Estolate is in a class of drugs called macrolide antibiotics and fights bacteria in the body. Erythromycin, Generic Erythromycin, Erythromycin Estolate is used to treat many different types of bacterial infections, such as tonsillitis, bronchitis, pneumonia, whooping cough, Legionnaire's disease, chlamydia, gonorrhea, skin infections, and others. Erythromycin, Generic Erythromycin, Erythromycin Estolate may also be used for purposes other than those listed in this medication guide. Take Erythromycin, Generic Erythromycin, Erythromycin Estolate exactly as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you. Symptoms of an Erythromycin, Generic Erythromycin, Erythromycin Estolate overdose include nausea, vomiting, diarrhea, and abdominal discomfort.