Erythromycin is also prescribed to prevent rheumatic fever in people who are allergic to penicillin and sulfa drugs. It is prescribed before colorectal surgery to prevent infection.

Most important fact about this drug

Erythromycin, like any other antibiotic, works best when there is a constant amount of drug in the blood. To help keep the drug amount constant, it is important not to miss any doses. Also, it is advisable to take the doses at evenly spaced times around the clock.

How should you take this medication?

Some forms of erythromycin are most effective when taken on an empty stomach. Your doctor may advise you to take each dose at least 1/2 hour and preferably 2 hours before meals. Delayed release formulations may be taken with or without food. If the drug upsets your stomach, taking it with meals may help. Ask your doctor whether this is advisable for you.

Chewable forms of erythromycin should be crushed or chewed before being swallowed.

Delayed-release brands and tablets and capsules that are coated to slow their breakdown should be swallowed whole. Do not crush or break. If you are not sure about the form of erythromycin you are taking, ask your pharmacist.

The liquid should be shaken well before each use.

• If you miss a dose...
  Take it as soon as you remember. If it is almost time for your next dose, and you take 2 doses a day, space the missed dose and the next dose 5 to 6 hours apart; if you take 3 or more doses a day, space the missed dose and the next one 2 to 4 hours apart. Never take 2 doses at the same time.

• Storage instructions...
  The liquid form of erythromycin should be kept in the refrigerator; use E.E.S. within 10 days. Do not freeze. Store tablets and capsules at room temperature in a tightly closed container.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine whether it is safe to continue taking this medication.

• Side effects may include:
  Abdominal pain, diarrhea, loss of appetite, nausea, vomiting

Why should this drug not be prescribed?

You should not use erythromycin if you have ever had an allergic reaction to it or are sensitive to it.

Special warnings about this medication

As with other antibiotics, treatment with erythromycin may result in a growth of bacteria that do not respond to this medication and can cause a secondary infection.

If you have ever had liver disease, consult your doctor before taking erythromycin.

If a new infection (called superinfection) develops, talk to your doctor. You may need to be treated with a different antibiotic.

This drug may cause a severe form of intestinal inflammation. If you develop diarrhea, contact your doctor immediately. If you have myasthenia gravis (muscle weakness), it can be aggravated by erythromycin.

When erythromycin is used to treat syphilis in pregnant women, it does not prevent the disease from infecting their babies. The infants should be treated after birth with penicillin.

Prolonged or repeated use of erythromycin may result in the growth of bacteria or fungi that do not respond to this medication and can cause a second infection.

Possible food and drug interactions when taking this medication

Combining erythromycin with lovastatin can cause severe muscle wasting and damage to the kidneys. If you are taking both of these drugs, your doctor will monitor you closely for warning signs of this interaction.

If erythromycin is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining erythromycin with the following:

Benzodiazepines such as midazolam and triazolam

Blood-thinning drugs such as warfarin

Bromocriptine

Carbamazepine

Cyclosporine

Digoxin

Dihydroergotamine

Disopyramide

Ergotamine

Hexobarbital

Seizure medications such as phenytoin and valproic acid

Tacrolimus

Theophylline

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Special information if you are pregnant or breastfeeding

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There is no evidence that erythromycin will harm a developing baby, but the possibility has not been completely ruled out. If you are pregnant or plan to become pregnant, inform your doctor immediately.

Erythromycin appears in breast milk and could affect a nursing infant. If this medication is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment is finished.

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Recommended dosage

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Dosage instructions are determined by the type (and severity) of infection being treated and may vary slightly for different brands of erythromycin. The following are recommended dosages for PCE, one of the most commonly prescribed brands.

ADULTS

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Streptococcal Infections

The usual dose is 333 milligrams every 8 hours, or 500 milligrams every 12 hours. Depending on the severity of the infection, the dose may be increased to a total of 4 grams a day. However, when the daily dosage is larger than 1 gram, twice-a-day doses are not recommended, and the drug should be taken more often in smaller doses.

To treat streptococcal infections of the upper respiratory tract (tonsillitis or strep throat), erythromycin should be taken for at least 10 days.

To prevent repeated infections in people who have had rheumatic fever, the usual dosage is 250 milligrams twice a day.

Urinary Tract Infections Due to Chlamydia Trachomatis During Pregnancy

The usual dosage is 500 milligrams of erythromycin orally 4 times a day or 666 milligrams every 8 hours on an empty stomach for at least 7 days. For women who cannot tolerate this regimen, a decreased dose of 500 milligrams every 12 hours or 333 milligrams every 8 hours a day should be used for at least 14 days.

For Those with Uncomplicated Urinary, Reproductive Tract, or Rectal Infections Caused by Chlamydia Trachomatis When Tetracycline Cannot Be Taken

The usual oral dosage is 500 milligrams of erythromycin 4 times a day or 666 milligrams every 8 hours for at least 7 days.

For Those with Nongonococcal Urethral Infections When Tetracycline Cannot Be Taken

The usual dosage is 500 milligrams of erythromycin by mouth 4 times a day or 666 milligrams orally every 8 hours for at least 7 days.

Acute Pelvic Inflammatory Disease Caused by Neisseria Gonorrhoeae

The usual treatment is three days of intravenous erythromycin followed by 500 milligrams orally every 12 hours or 333 milligrams orally every 8 hours for 7 days.

Syphilis

The usual dosage is 30 to 40 grams divided into smaller doses over a period of 10 to 15 days.

Intestinal Infections

The usual dosage is 500 milligrams every 12 hours, or 333 milligrams every 8 hours, for 10 to 14 days.

Legionnaires' Disease

The usual dosage ranges from 1 to 4 grams daily, divided into smaller doses.

CHILDREN

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Age, weight, and severity of the infection determine the correct dosage.

The usual dosage is from 30 to 50 milligrams daily for each 2.2 pounds of body weight, divided into equal doses for 10 to 14 days. For pneumonia in infants due to chlamydia, treatment lasts at least 3 weeks.

For more severe infections, this dosage may be doubled, but it should not exceed 4 grams per day.

Children weighing over 44 pounds should follow the recommended adult dose schedule.

For prevention of bacterial endocarditis, the children's dosage is 10 milligrams per 2.2 pounds of body weight 2 hours before dental work or surgery, followed by 5 milligrams per 2.2 pounds 6 hours later.

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Overdosage

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Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical help immediately.

• Symptoms of erythromycin overdose may include:
  Diarrhea, nausea, stomach cramps, vomiting