Medications and Drugs

Anatomy of a Sore Throat Natural Cold Flu Remedies Slideshow The Common Cold Slideshow

Pharmacy Author: Annette O. Gbemudu PharmD, MBA
Medical and Pharmacy Editor: Jay W. Marks, MD

GENERIC NAME: erythromycin

BRAND NAMES: E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone

DRUG CLASS AND MECHANISM: Erythromycin is an antibiotic in the class of antibiotics known as macrolide antibiotics which also includes azithromycin (Zithromax, Zmax) and clarithromycin (Biaxin). It is used to treat several types of infections--upper/lower respiratory tract infections, skin infections, acute pelvic inflammatory disease, erythrasma, etc. caused by bacteria such as Streptococcus pyogenes, Streptococcus pneumoniae, Mycoplasma pneumoniae, Staphylococcus aureus, Neisseria gonorrhoeae, and many others. Erythromycin, like all macrolide antibiotics, prevents bacterial cells from growing and multiplying by interfering with their ability to make proteins while not affecting human cells. Bacteria such as Haemophilus influenzae are resistant to erythromycin alone and must be treated with a combination of erythromycin and adequate doses of sulfonamides.

PRESCRIPTION: Yes

GENERIC AVAILABLE: Yes

PREPARATIONS: Tablets: 250, 333, 400 and 500 mg. Suspension: 200 mg/teaspoon, 400 mg/teaspoon. Powder: 100 mg/half-teaspoon, 200 mg/teaspoon. Granules: 200 mg/teaspoon, 400 mg/teaspoon. Powder for Injection: 500 mg, 1g.

STORAGE: Erythromycin should be stored at temperatures below 86 F (30 C). It is important to protect tablets from moisture and excessive heat.

PRESCRIBED FOR: Erythromycin is used to treat streptococcal infections of the throat ("strep throat") and skin. It is used for infections of the lung (pneumonia) caused by streptococcal pneumoniae, mycoplasma pneumoniae, and legionella pneumophila (legionnaires disease). Erythromycin is used to treat acute pelvic inflammatory disease, diphtheria, erythrasma, whooping cough, listeriosis, and intestinal amebiasis. It is used for the treatment of staphylococcal infections of the skin and as an alternative antibiotic for the treatment of syphilis, gonorrhea, and chlamydia. Erythromycin is used in patients who are allergic to penicillin for the prevention of recurrent rheumatic fever and infections of the hearts' valves (endocarditis) in patients with valvular abnormalities of the heart before they undergo dental treatments. The non-FDA approved uses for erythromycin include acne, Lyme disease, and tetanus.

DOSING: The usual dosage for adults is 250 mg every 6 hours, 333 mg every 8 hours or 500 mg every 12 hours. Doses may be increased up to 4 g/day according to the severity of the infection.

In children, the usual dosage is 30 to 50 mg/kg/day with age, weight, and severity of the infection being taken into consideration to determine the appropriate dosage.

Erythromycin may be taken with or without food; however optimal blood levels of erythromycin are obtained when taken on an empty stomach (at least 30 minutes and preferably 2 hours before or after meals).

Report Problems to the Food and Drug Administration   You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.