Erythromycin

Erythromycin is an antibiotic useful for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the newborn. Erythromycin may be used to improve delayed stomach emptying. It can be given intravenously and by mouth. An eye ointment is routinely recommended after delivery to prevent eye infections in the newborn.
Common side effects include abdominal cramps, vomiting, and diarrhea. More serious side effects may include Clostridium difficile colitis, liver problems, prolonged QT, and allergic reactions. It is generally safe in those who are allergic to penicillin. Erythromycin also appears to be safe to use during pregnancy. While generally regarded as safe during breastfeeding its use by the mother during the first two weeks of life may increase the risk of pyloric stenosis in the baby. This risk also applies if taken directly by the baby during this age. It is in the macrolide family and works by decreasing the making of protein by bacteria.
Erythromycin was first isolated in 1952 from the bacteria Saccharopolyspora erythraea. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. It is available as a generic medication and is not very expensive. The wholesale price in the developing world is between 0.03 and 0.06 USD per tablet.