Erythromycin ethylsuccinate belongs to the class of medications known as macrolide antibiotics. It works by killing the bacteria or preventing their growth. It is used to treat many bacterial infections, including chest infections such as pneumonia, skin infections, throat infections such as strep throat, diphtheria, ear infections, and certain sexually transmitted infections such as syphilis or chlamydia.

Erythromycin ethylsuccinate may also be used to prevent heart problems after dental work for people with heart disease.

Under normal circumstances, your infection should improve (e.g., reduced symptoms or temperature) within 24 to 48 hours. If this does not happen, call your doctor. Like other antibiotics, erythromycin ethylsuccinate is not effective against viruses such as those that cause the common cold.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Adults and adolescents: The recommended dose of erythromycin ethylsuccinate for adults and teenagers ranges from 400 mg to 800 mg 2 to 4 times daily depending on the condition being treated.

Children: Doses for children are based on body weight. The usual daily dose is 30 mg to 50 mg of erythromycin ethylsuccinate per each kilogram of body weight. This dose should be taken in 2 to 4 evenly divided doses.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Erythromycin ethylsuccinate is best taken with a full glass (8 ounces) of water immediately after food.

Shake the liquid form of the medication well before each use and measure the dose accurately with a suitable oral syringe or other accurate measuring device.

Erythromycin ethylsuccinate must be taken regularly as prescribed so that blood levels of the medication always remain high enough to be effective.

Erythromycin ethylsuccinate must be taken for the recommended duration of treatment, even if you are feeling better. This will ensure that any lingering bacteria cannot grow back.

Keep the liquid form of erythromycin ethylsuccinate in the refrigerator but do not allow it to freeze. Discard any portion of refrigerated medication that has not been consumed within 14 days.

Keep the tablet form of the medication at room temperature and away from heat and direct light. Do not store erythromycin ethylsuccinate in the bathroom or near the kitchen sink, as moisture may cause the medication to break down.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Erythromycin ethylsuccinate should not be taken by anyone who:

• is allergic to erythromycin ethylsuccinate or to any ingredients of the medication
• is allergic to clarithromycin, azithromycin, or other macrolide antibiotics
• is taking astemizole, terfenadine, or cisapride, ergotamine, or dihydroergotamine
• has an infection caused by microorganisms that are resistant to erythromycin

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal or stomach cramping and discomfort
• decrease in appetite
• diarrhea
• nausea or vomiting sore mouth or tongue
• vaginal itching and discharge

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• fainting (repeated)
• fever
• irregular or slow heartbeat
• loss of hearing (temporary)
• severe diarrhea
• severe nausea or vomiting
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin rash, redness, or itching
• stomach pain (severe)
• unusual tiredness or weakness

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (i.e., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergy: Anyone who has had any form of allergy to medications should be carefully monitored when taking erythromycin. If you experience symptoms of an allergic reaction to erythromycin, such as abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat, stop taking it and contact your doctor.

Heart conditions: Antibiotics in the same class as erythromycin ethylsuccinatecan cause an abnormal heart rhythm and should be avoided by people with certain heart rhythm problems, especially long QT syndrome, congenital QT interval prolongation, and bradycardia (low heart rate). There have been a few reports of long QT syndrome occurring with people taking erythromycin ethylsuccinate. People who have had irregular heart rhythms caused by other medications in the past should avoid taking this medication. It should also be avoided by people with low blood potassium or magnesium levels, and by people taking certain medications used to treat irregular heart rhythms (e.g., quinidine, procainamide, amiodarone, sotalol). If you experience an irregular heartbeat, stop taking this medication and contact your doctor.

Liver problems: There have been reports of liver problems occurring in a small percentage of people taking erythromycin products. People with liver disease or reduced liver function should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Anyone who experiences symptoms of decreased liver function, such as yellowing of the skin or whites of the eyes, dark urine, or pale stools, should contact their doctor as soon as possible.

Myasthenia gravis: People taking erythromycin ethylsuccinate have on occasionally reported worsening of their symptoms. People with myasthenia gravis should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Overgrowth of organisms: Prolonged or repeated use of erythromycin may result in an overgrowth of bacteria or fungi and organisms that are not killed by the medication. This can cause problems such as yeast infections.

Pregnancy: The safety of erythromycin for use during pregnancy has not been established. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: The safety of erythromycin for use during breast-feeding has not been established. It passes into breast milk and may affect the infant. If you are a breast-feeding mother and are taking this medication, talk to your doctor about whether you should continue breast-feeding.

Children: The safety of erythromycin for use by newborns has not been established.

Seniors: Seniors taking erythromycin ethylsuccinate may be at increased risk of side effects as a result of drug interactions with other medications they may be taking.

There may be an interaction between erythromycin ethylsuccinate and any of the following:

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.