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AHFS Consumer Medication Information [Internet]. Bethesda (MD): American Society of Health-System Pharmacists; 2000-2011.

AHFS Consumer Medication Information.

Erythromycin(er ith roe mye' sin)

Last reviewed: September 1, 2010.

Why is this medication prescribed?

Erythromycin is an antibiotic used to treat certain infections caused by bacteria, such as bronchitis; diphtheria; Legionnaires' disease; pertussis (whooping cough); pneumonia; rheumatic fever; venereal disease (VD); and ear, intestine, lung, urinary tract, and skin infections. It is also used before some surgery or dental work to prevent infection. Antibiotics will not work for colds, flu, or other viral infections.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Erythromycin comes as a capsule, tablet, long-acting capsule, long-acting tablet, chewable tablet, liquid, and pediatric drops to take by mouth. It usually is taken every 6 hours (four times a day) or every 8 hours (three times a day) for 7-21 days. Some infections may require a longer time. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take erythromycin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Shake the liquid and pediatric drops well before each use to mix the medication evenly. Use the bottle dropper to measure the dose of pediatric drops.

The chewable tablets should be crushed or chewed thoroughly before they are swallowed. The other capsules and tablets should be swallowed whole and taken with a full glass of water.

Continue to take erythromycin even if you feel well. Do not stop taking erythromycin without talking to your doctor.

What special precautions should I follow?

Before taking erythromycin,

  • tell your doctor and pharmacist if you are allergic to erythromycin, azithromycin (Zithromax), clarithromycin (Biaxin), dirithromycin (Dynabac), or any other drugs.

  • tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially other antibiotics, anticoagulants ('blood thinners'), astemizole (Hismanal), carbamazepine (Tegretol), cisapride (Propulsid), clozapine (clozaril), cyclosporine (Neoral, Sandimmune), digoxin (Lanoxin), disopyramide (Norpace), ergotamine, felodipine (Plendil), lovastatin (Mevacor), phenytoin (Dilantin), pimozide (Orap), terfenadine (Seldane), theophylline (Theo-Dur), triazolam (Halcion), and vitamins.

  • tell your doctor if you have or have ever had liver disease, yellowing of the skin or eyes, colitis, or stomach problems.

  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking erythromycin, call your doctor.

  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking erythromycin.

What special dietary instructions should I follow?

Take erythromycin at least 1 hour before or 2 hours after meals. Do not take this medication with, or just after, fruit juices or carbonated drinks. Certain brands of erythromycin may be taken with meals; check with your doctor or pharmacist.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Erythromycin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • upset stomach

  • diarrhea

  • vomiting

  • stomach cramps

  • mild skin rash

  • stomach pain

If you experience any of the following symptoms, call your doctor immediately:

  • severe skin rash

  • itching

  • hives

  • difficulty breathing or swallowing

  • wheezing

  • yellowing of the skin or eyes

  • dark urine

  • pale stools

  • unusual tiredness

  • vaginal infection

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store the capsules and tablets at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Keep liquid medicine in the refrigerator, closed tightly, and throw away any unused medication after 14 days. Do not freeze. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to erythromycin.

Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the erythromycin, call your doctor.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS® Consumer Medication Information. © Copyright, 2011. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

The following brand names are from RxNorm, a standardized nomenclature for clinical drugs produced by the National Library of Medicine:

Brand names

  • E-Mycin

  • E.E.S.

  • Ery-Tab

  • EryPed

  • Eryc

  • Erythrocin Stearate

  • Erythrocot

  • Ilosone

  • MY-E

  • PCE

  • Robimycin

Brand names of combination products

  • E.S.P. (containing Erythromycin and Sulfisoxazole)

  • Eryzole (containing Erythromycin and Sulfisoxazole)

  • Pediazole (containing Erythromycin and Sulfisoxazole)

  • Sulfimycin (containing Erythromycin and Sulfisoxazole)

What works?

  • Erythromycin for preventing and treating preterm infants with feeding difficulties Erythromycin for preventing and treating preterm infants with feeding difficulties
    There is not enough evidence to show any benefit from erythromycin used in large or small doses for the prevention or treatment of feeding problems in premature infants. Premature infants who need intensive care often have feeding problems. Frequently, some food stays in the stomach without being digested. Earlier feeding can facilitate normal development of the gastrointestinal tract and can avoid health problems related to feeding by intravenous lines. Erythromycin is an antibiotic that has an effect on the gastrointestinal tract and may help infants with feeding problems. However, this review found that there is not enough evidence to recommend the use of erythromycin in small or large doses to prevent or treat premature infants with feeding problems.
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