Erythromycin dosage for adults

Capsule or tablet, 250 mg (as stearate or ethyl succinate)
Powder for oral suspension, 125 mg (as stearate or ethyl succinate)
Eye ointment, 1%

General information

Erythromycin is a macrolide antibiotic produced by Streptomyces erythreus. It has selective bacteriostatic activity against both streptococci and staphylococci and some Gram-positive bacilli.

Because erythromycin is inactivated by gastric juices, oral formulations are protected by an enteric coating. The drug diffuses rapidly into all tissues except the brain and cerebrospinal fluid, and readily crosses the placental barrier. The plasma half-life is approximately 90 minutes. Erythromycin is partially demethylated in the liver and excreted largely via the bile and faeces.

Clinical information

Uses

Treatment of:

• acute pharyngitis and acute cervical adenitis in patients allergic to penicillins

• diphtheria and legionellosis

• pneumonia in adults and children > 5 years

• atypical pneumonia in adults and children > 5 years, together with either chloramphenicol or cefuroxime or ceftriaxone or benzylpenicillin or benzylpenicillin plus gentamicin

• pertussis (whooping cough) in children

• ornithosis and Q fever in children ≤ 8 years

• gingival infections and periodontitis

• enteritis due to Campylobacter jejuni

• prostatitis due to Chlamydia trachomatis or Ureaplasma urealyticum and chancroid in adults

• lymphogranuloma venereum, chlamydial ophthalmia, other chlamydial infections, and syphilis in patients allergic to penicillins

• relapsing fever.

Prevention of neonatal gonococcal conjunctivitis and recurrence of rheumatic fever due to group A β-haemolytic streptococci in patients allergic to penicillins.

Postsplenectomy prophylaxis.

Dosage and administration

Erythromycin tablets should not be broken in half before administration.

Acute pharyngitis and acute cervical adenitis in patients allergic to penicillins

Adults: 500 mg orally every 6 hours for 10 days.

Children: 10 – 15mg/kg (maximum 500 mg) orally every 6 hours for 10 days.

Diphtheria

Adults: 500 mg orally every 6 hours for 7 days, following initial therapy with diphtheria antitoxin 20 000 – 100 000IU i.v. or i.m.

Children: 10 – 15mg/kg (maximum 500mg) orally every 6 hours for 7 days, following initial therapy with diphtheria antitoxin 20 000 – 100 000IU i.v. or i.m.

Vaccination with diphtheria – pertussis – tetanus should be offered during convalescence.

Pneumonia in adults and children > 5 years

Ambulatory patients

Adults: 500 mg orally every 6 hours for 5 days.

Children > 5 years: 10 – 15mg/kg (maximum 500mg) orally every 6 hours for 5 days.

Patients with atypical pneumonia should receive treatment for 14 days.

Hospitalized patients with atypical pneumonia

Legionellosis

Adults: 1g i.v. every 6 hours for 10 days (once clinical improvement occurs, 500mg orally every 6 hours may be substituted).

Pertussis (whooping cough) in children

50mg/kg (maximum 2g) orally in 4 divided doses daily for 14 days.

Ornithosis and Q fever in children ≤ 8 years

10 – 15mg/kg (maximum 500mg) orally every 6 hours for 7 – 10 days.

Gingival infections and periodontitis

Adults: 250 mg orally every 6 hours for 5 days.

Children: 7.5mg/kg (maximum 250mg) orally every 6 hours for 5 days.

Enteritis due to Campylobacter jejuni

Adults: 500 mg orally every 6 hours for 7 – 10 days.

Children: 10mg/kg (maximum 500mg) orally every 6 hours for 7 – 10 days.

Prostatitis due to Chlamydia trachomatis or Ureaplasma urealyticum in adults

500 mg orally every 6 hours for 14 days.

Lymphogranuloma venereum

Adults: 500 mg orally every 6 hours for 14 days.

Children: 12.5mg/kg (maximum 500mg) orally every 6 hours for 14 days.

Chlamydial ophthalmia

12.5 mg/kg (as syrup; maximum 500mg) orally every 6 hours for 14 days.

Other chlamydial infections

Adults: 500 mg orally every 6 hours for 7 days.

Children: 10 – 15mg/kg (maximum 500mg) orally every 6 hours for 7 days.

Syphilis in patients allergic to penicillins

Adults: 500 mg orally every 6 hours for 15 days.

Children: 7.5 – 12.5mg/kg (maximum 250mg) orally every 6 hours for 30 days.

Chancroid in adults

500mg orally every 6 hours for 7 days. (Longer treatment courses may be necessary in immunocompromised patients.)

Relapsing fever

Adults: 500 mg orally in a single dose.

Children: 12.5mg/kg (maximum 500mg) orally in a single dose.

Prevention of neonatal gonococcal conjunctivitis

A single application of eye ointment immediately after birth should be sufficient.

Prevention of recurrence of rheumatic fever due to group A β-haemolytic streptococci in patients allergic to penicillins

Adults and children: 250 mg orally every 12 hours.

Postsplenectomy prophylaxis

Adults: 250 mg orally every 24 hours.

Children: 7.5mg/kg (maximum 250mg) orally every 24 hours.

Contraindications

Known hypersensitivity to erythromycin or other macrolides.

Precautions

Hepatic function should be monitored in patients with a previous history of liver disease.

Use in pregnancy

Erythromycin has not been shown to be mutagenic, teratogenic or embryotoxic; it can be used during pregnancy.

Adverse effects

Nausea, vomiting and diarrhoea can occur.

Cholestatic hepatitis, which may present with symptoms suggestive of acute cholecystitis, occasionally complicates prolonged courses of treatment. Symptoms resolve rapidly when the drug is withdrawn.

Anaphylaxis and other hypersensitivity reactions are rare.

Drug interactions

Erythromycin, chloramphenicol and clindamycin have a similar bacteriostatic action and tend to be mutually antagonistic when administered together. Erythromycin decreases the rate of metabolism of carbamazepine and warfarin in the liver to a degree that can warrant readjustment of dosage.

Overdosage

Symptoms of overdosage include severe nausea, vomiting, diarrhoea and hearing loss. Induction of emesis or gastric lavage may be of value if undertaken within a few hours of ingestion.

Storage

Capsules and tablets should be stored in tightly closed containers. Suspension and eye ointment should be stored in well-closed containers protected from light.

Combining Antibiotics and Alcohol: Is It Safe?

Alcohol doesn’t make antibiotics less effective, but consuming alcohol — especially if you drink too much — might increase your chance of experiencing certain side effects.

You should never consume alcohol while taking any of the following antibiotics:

  • cefoperazone
  • cefotetan
  • doxycycline
  • erythromycin
  • metronidazole
  • tinidazole
  • ketoconazole
  • isoniazid
  • linezolid
  • griseofulvin

Combining these antibiotics and alcohol can cause a potentially dangerous reaction.

Metronidazole, tinidazole, cefoperazone, cefotetan, and ketoconazole

Drinking alcohol while taking these drugs can cause:

  • nausea
  • vomiting
  • flushing
  • headache
  • fast heartbeat
  • stomach cramps

Don’t drink alcohol before, during, or up to three days after taking these drugs.

Griseofulvin

Drinking alcohol while taking this medication can cause:

  • flushing
  • excessive sweating
  • fast heartbeat

Isoniazid and linezolid

Drinking alcohol with these medications can cause side effects such as:

  • liver damage
  • high blood pressure

Doxycycline and erythromycin

Drinking alcohol while taking these antibiotics may make them less effective.

General side effects

The specific side effects that an antibiotic can cause depends on the drug. However, some common side effects of antibiotics include:

  • nausea
  • sleepiness
  • dizziness
  • lightheadedness
  • diarrhea

Alcohol can also cause side effects. These include:

  • an upset stomach
  • digestive problems, such as stomach pain, diarrhea, and ulcers
  • tiredness

Signs of a negative alcohol-antibiotic reaction include:

  • flushing (reddening and warming of your skin)
  • severe headache
  • racing heart rate

In most cases, these side effects go away on their own. If you think you’re having a medical emergency, call 911 or your local emergency services number immediately.

What to do

The warning label on your antibiotic should include information about alcohol use.

Talk to your doctor or pharmacist if you’re unsure about the details of your medications. They may tell you that an occasional drink is OK. But that likely depends on your age, overall health, and the type of drug you’re taking.

If your doctor tells you that you shouldn’t drink alcohol, ask how long you should wait before drinking again. You may need to wait at least 72 hours after finishing your course of antibiotics before having any alcohol.

Listening to your doctor or pharmacist’s advice can help you avoid the effects of an alcohol-drug interaction.

  1. What is erythromycin?
  2. What is erythromycin used for?
  3. Key facts
  4. How does erythromycin work?
  5. Who can and can’t take erythromycin?
  6. Can I take erythromycin while pregnant or breastfeeding?
  7. Dosage: How do I take erythromycin and how often?
  8. Can I drink alcohol with erythromycin?
  9. What are the side effects of erythromycin?
  10. Can I take other medicines with erythromycin?

Erythromycin is an antibiotic medicine commonly prescribed for chest infections, ear infections, some sexually-transmitted infections and skin infections, particularly in people who are allergic to penicillin. It’s also used for acne and acne rosacea.

Erythromycin comes as tablets (250mg and 500mg strengths) and liquid. It may be given by injection in hospital.

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What is erythromycin used for?

Erythromycin tablets, liquid and injection are used to treat infections caused by bacteria, such as:

  • Chest infections, eg bronchitis, bronchiectasis, pneumonia, Legionnaires’ disease.
  • Whooping cough. Erythromycin is also used to prevent whooping cough in people who’ve been exposed to whooping cough and haven’t been vaccinated against it.
  • Infections of the nasal passages, sinuses or throat, eg sinusitis, pharyngitis, laryngitis, tonsillitis.
  • Ear infections, eg otitis media or otitis externa.
  • Mouth infections, eg gum disease (gingivitis), dental abscesses.
  • Infections of skin or soft tissue, eg boils, abscesses, cellulitis, impetigo, erysipelas.
  • Infections in the stomach and intestines, eg Campylobacter enteritis.
  • Infections of the urethra (urethritis) or prostate gland (prostatitis).
  • Chlamydia.
  • Syphilis.
  • Diphtheria.
  • Scarlet fever.
  • Acne (spots).
  • Acne rosacea.

Erythromycin is also used prevent bacterial infection following surgery, burns or trauma.

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Erythromycin works on the same types of bacteria as penicillin, so it’s useful for treating infections in people who are allergic to penicillin antibiotics.

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💡Key facts

  • Erythromycin is only available on prescription.
  • Erythrocin and Erythroped are brand names for erythromycin.
  • Erythromycin is suitable for children of all ages and adults, including pregnant and breastfeeding women.
  • It’s usual to take a dose two or four times a day for infections and twice a day for acne.
  • Try to space your doses at regular intervals over the day. Always complete the prescribed course.
  • The most common side effects are feeling sick or vomiting, tummy ache and diarrhoea. See a doctor as soon as possible if you get diarrhoea that is severe, persistent or contains blood/mucus.
  • It’s usually OK to drink small amounts of alcohol while taking erythromycin. See below.

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How does erythromycin work?

Erythromycin is a type of medicine called a macrolide antibiotic. It works by stopping bacteria from producing essential proteins. Without these proteins the bacteria cannot grow, replicate and increase in numbers. This clears up the infection.

Erythromycin is a broad-spectrum antibiotic, which means it can treat infections caused by a wide variety of bacteria. However, it does not kill viruses and will not work to treat viral infections, such as colds, flu and most coughs and sore throats.

To make sure the bacteria causing an infection are susceptible to erythromycin your doctor may take a tissue sample, for example a swab from the throat or skin.

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For acne:

Erythromycin is also active against the bacteria associated with acne, Propionebacterium acnes. This is a common type of bacteria that feeds on sebum produced by the sebaceous glands in the skin. It produces waste products and fatty acids that irritate the sebaceous glands, making them inflamed and causing spots. By controlling bacterial numbers, erythromycin brings the inflammation of the sebaceous glands under control, and allows the skin to heal. (Other antibiotics may be preferred for acne however, as strains of the Propionebacterium that are resistant to erythromycin are becoming widespread.)

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Who can and can’t take erythromycin?

Erythromycin is suitable for children of all ages and adults, including women who are pregnant or breastfeeding. It can be taken by most people, but may not be suitable if you:

  • are taking certain other medicines – see end of page for more information.
  • are allergic to any ingredients of the medicine.

Some people may need a lower erythromycin dose or extra monitoring. Make sure your doctor knows if you:

  • have liver or kidney problems.
  • have an abnormal heart rhythm seen on a heart monitoring trace (ECG) as a ‘prolonged QT interval’, or people at risk of this (your doctor will know).
  • suffer from a condition called myasthenia gravis in which there is abnormal muscle weakness.
  • have a rare inherited blood disorder called porphyria.

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Can I take erythromycin while pregnant or breastfeeding?

Yes – erythromycin is not known to be harmful when taken by women who are pregnant or or breastfeeding.

Erythromycin passes into breast milk in small amounts. Although it’s not known to be harmful to a nursing infant, you should let your doctor know if you think your baby has developed diarrhoea, thrush or nappy rash if you are breastfeeding while taking a course of erythromycin. Ask your doctor for further advice.

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Dosage: How do you take erythromycin and how often?

The dose of erythromycin your doctor prescribes, how often to take it and how long for, depends on what you’re taking this antibiotic for, your age and your kidney function. Always follow the instructions given by your doctor. These will be printed on the label that your pharmacist has put on the packet of medicine.

  • Erythromycin is usually taken two or four times a day for infections and twice a day for acne. Space your doses evenly over the day.
  • You can take erythromycin either with or without food. If you find it upsets your stomach, taking it with food may help.
  • If you’ve been given erythromycin gastro-resistant tablets, swallow these whole with a drink. Do not break, crush or chew them. Don’t take indigestion remedies (antacids) in the two hours before or after taking this type of erythromycin tablet.
  • If you’ve been given erythromycin liquid make sure you shake the bottle before measuring out a dose. Only use the measuring spoon or oral syringe provided with the suspension. Don’t use a regular teaspoon or tablespoon to give the medicine, as this won’t give an accurate dose.

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If you forget to take a dose at the correct time you should take it as soon as you remember, and then space the rest of the day’s doses over the remainder of the day. Don’t take two doses at the same time to make up for a missed dose.

To treat an infection your doctor may prescribe you a course of erythromycin that lasts between 5 and 14 days. Unless your doctor tells you otherwise, it’s important to finish the prescribed course, even if you feel better or it seems the infection has cleared up. Stopping the course early increases the chance that the infection will come back and that the bacteria will grow resistant to the antibiotic.

For acne and rosacea you’ll need to take erythromycin regularly for longer periods of time – usually 6 to 12 weeks for rosacea and a few months for acne.

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Can I drink alcohol with erythromycin?

It’s possible that drinking alcohol could slightly reduce the absorption of erythromycin from your gut, which might make it slightly less effective. However there are no specific warnings about avoiding alcohol while you’re taking erythromycin.

If you feel unwell with your infection, or if you find erythromycin gives you an upset stomach, then drinking alcohol could make this worse.

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What are the side effects of erythromycin?

Prolonged treatment with antibiotics can sometimes cause overgrowth of other organisms that are not susceptible to the antibiotic, for example fungi or yeasts such as Candida. This may sometimes cause infections such as thrush. Tell your doctor if you think you have developed a new infection during or after taking this antibiotic.

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The following are some of the side effects that may be associated with erythromycin. Just because a side effect is stated here doesn’t mean that all people taking erythromycin will experience that or any side effect. Medicines can affect individual people in different ways.

Common erythromycin side effects

  • Feeling sick.
  • Vomiting.
  • Stomach ache.
  • Diarrhoea.

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Other possible side effects

  • Allergic reactions. See a doctor straight away if you get a skin rash or itching, breathing problems or swelling of the face, throat or tongue while taking erythromycin.
  • Inflammation of the large intestine (pseudomembranous colitis). Tell your doctor if you get severe, prolonged or bloody diarrhoea during or after a course of erythromycin. Don’t take a medicine to stop the diarrhoea such as loperamide.
  • Liver problems such as jaundice or inflammation of the liver (hepatitis). See your doctor if you get unexplained itching, sickness and vomiting, abdominal pains, loss of appetite, flu-like symptoms, yellowing of the skin or whites of the eyes, or unusually dark urine.
  • Palpitations, chest pains or a faster or irregular heartbeat. Tell your doctor if you experience this.

Read the leaflet that comes with your medicine or talk to your doctor, nurse or pharmacist if you want any more information about the possible side effects of erythromycin. If you think you have experienced a side effect, did you know you can report this using the yellow card website?

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Can I take erythromycin with other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with erythromycin. Similarly, ask your doctor or pharmacist before taking any new medicines while taking erythromycin, so they can check that the combination is safe. Some key points are:

Don’t take erythromycin if you’re taking any of the following medicines, because the combination carries a risk of serious side effects:

  • amisulpride
  • astemizole
  • cisapride
  • domperidone
  • eletriptan
  • ergotamine
  • dihydroergotamine
  • dronedarone
  • ivabradine
  • lercanidipine
  • lomitapide
  • mizolastine
  • pimozide
  • quetiapine
  • rilpivirine
  • saquinavir
  • sertindole
  • simeprevir
  • simvastatin
  • terfenadine
  • tolterodine
  • vinblastine.

Indigestion remedies

Don’t take antacids for indigestion in the two hours before or after taking gastro-resistant erythromycin tablets.

Painkillers

If you need to ease pain or lower a high temperature (fever), it’s fine to take paracetamol or ibuprofen with erythromycin.

Contraception

Erythromycin doesn’t affect hormonal contraceptives such as the pill. However, if you experience vomiting or diarrhoea while taking this antibiotic, this can potentially make your pill less effective at preventing pregnancy. If this happens to you, follow the instructions for vomiting and diarrhoea described in the leaflet provided with your pills.

Anticoagulants

Erythromycin may increase the anti-blood-clotting effects of nicoumalone and warfarin, which could increase the risk of bleeding. If you’re taking one of these medicines your doctor may want to check your blood clotting time (INR) while you take a course of erythromycin so your dose of anticoagulant can be adjusted if necessary.

Statins

If you’re taking a cholesterol-lowering medicine known as a statin, eg atorvastatin or lovastatin, taking erythromycin as well might increase the risk of getting side effects on your muscles. Your doctor may want you to stop taking your statin temporarily while you take a course of this antibiotic.

Vaccines

Oral typhoid vaccine (Vivotif) should not be taken until at least three days after you have finished a course of erythromycin, because the antibiotic could make this vaccine less effective.

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Erythromycin may reduce the breakdown of the medicines listed below, which may increase the risk of their side effects. If you’re taking one of these and are prescribed erythromycin, tell your doctor or pharmacist know if you get any new or increased side effects:

  • alfentanil
  • alprazolam
  • axitinib
  • avanafil
  • bedaquiline
  • bosutinib
  • bromocriptine
  • buspirone
  • cabergoline
  • cabozantinib
  • carbamazepine
  • ciclosporin
  • cilostazol
  • clozapine
  • colchicine
  • dapoxetine
  • darifenacin
  • dasatinib
  • digoxin
  • disopyramide
  • eplerenone
  • everolimus
  • felodipine
  • galantamine
  • ibrutinib
  • ivacaftor
  • lurasidone
  • methylprednisolone and possibly other corticosteroids
  • midazolam
  • phenytoin
  • pravastatin
  • quetiapine
  • reboxetine
  • rifabutin
  • rupatadine
  • sildenafil
  • sirolimus
  • tacrolimus
  • tadalafil
  • theophylline (in addition theophylline may reduce the absorption of erythromycin taken by mouth, making it less effective)
  • triazolam
  • ulipristal
  • valproate
  • vardenafil
  • verapamil
  • zopiclone.

The following medicines may increase the blood level of erythromycin, which may increase the risk of its side effects:

  • cimetidine
  • protease inhibitors for HIV infection, such as ritonavir, lopinavir, saquinavir and amprenavir.

There may be an increased risk of abnormal heart beats if erythromycin is taken in combination with any of the following medicines (this is less likely with erythromycin taken by mouth than with erythromycin given by injection):

  • amiodarone
  • arsenic trioxide
  • atomoxetine
  • certain antimalarials, eg chloroquine, quinine, mefloquine, halofantrine
  • certain antipsychotics, eg chlorpromazine, thioridazine, fluphenazine, haloperidol
  • citalopram
  • delamanid
  • disopyramide
  • droperidol
  • escitalopram
  • moxifloxacin
  • pentamidine
  • quinidine
  • telaprevir
  • vandetanib.

Further reading

Last updated 07.03.2019

Helen Marshall, BPharm, MRPharmS Helen Marshall, BPharm, MRPharmS A UK registered pharmacist with a background in hospital pharmacy.

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