Medications and Drugs
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).
DRUG INTERACTIONS: Erythromycin when used with antiarrhythmic drugs such as,
amiodarone (Cordarone), bretylium (Bretylol),
disopyramide (Norpace),
dofetilide
(Tikosyn), procainamide (Pronestyl), quinidine (Quinaglute, Quinidex, Quinora)
and sotalol (Betapace) exaggerates the effect of the antiarrhythmic drugs which
may give rise to abnormal heart rhythms such as torsades de pointes.
Theophyllines such as theophylline (Theo-Dur), oxtriphylline (Choledyl SA),
and aminophylline (Phyllocontin) reduce erythromycin blood levels by increasing
elimination of erythromycin by the kidneys, which may reduce the effectiveness
of erythromycin. Conversely, erythromycin inhibits the metabolism (breakdown) of
theophyllines by the liver and causes an increase in blood levels of
theophylline. High theophylline levels may give rise to side effects such as
seizures and disturbances in heart rhythm. Therefore, the dose of theophyllines
should be reduced or theophylline levels in the blood should be measured in
patients taking erythromycin.
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.
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