Erythromycin is available in a variety of forms, including liquids, tablets, and capsules, but can only be obtained with a medical prescription. A particularly popular type of the drug is the delayed release tablet, which features a special coating that slows the breakdown of active ingredients, aiding in the maintenance of a constant, even supply of the antibiotic in the body. Some of the relatively common side effects that may occur with this and other varieties of erythromycin include nausea, fever, skin rash, and swelling. In rare cases, allergic reaction to the drug may result in temporary hearing loss, anaphylactic shock, or various other serious medical problems.