Possible Side Effects Erythromycin
Check with your doctor if any of these most common side effects persist or become bothersome:* diarrhea; loss of appetite; nausea; stomach pain; vomiting. Seek medical attention right away if any of these severe side effects occur: * severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools; hearing changes; irregular heartbeat; red, swollen, or blistered skin; severe diarrhea; severe stomach pain or cramps; yellowing of skin or eyes.

Drug Class and Mechanism Erythromycin
Erythromycin is a macrolide antibiotic. Macrolide antibiotics slow the growth of, or sometimes kill, sensitive bacteria by reducing the production of important proteins needed by the bacteria to survive.

More InformationErythromycin here
Erythromycin is to be used only by the patient for whom it is prescribed. Do not share it with other people. If your symptoms do not improve or if they become worse, check with your doctor.