Discovered in 1980, Azithromycin is an antibiotic used for the treatment of certain bacterial infections, such as middle ear infections, strep throat, pneumonia and traveler's diarrhea, among others. This medication basically works by preventing bacteria from producing proteins that are essential to them. In fact, without these proteins the bacteria cannot grow, replicate and increase in numbers. Of course, without this ability the bacteria will eventually die, or end up being destroyed by the immune system. When it comes to its common side effects, Azithromycin may cause nausea, vomiting, diarrhea and upset stomach. As a matter of fact, no harm has been found with its use during pregnancy, even though its safety during breastfeeding is yet to be confirmed.