Erythromycin: Uses, Dosage, Side Effects, Interactions, Warnings and Precautions

It is a drug used to treat a wide variety of bacterial infections.

It can also be used to prevent them. Erythromycin is known as a macrolide antibiotic. It works by stopping the growth of bacteria.

The medication is prescribed for infections such as pneumonia, whooping cough, sexually transmitted diseases, Legionnaires’ disease, urinary tract infections (UTIs), and acne.

For use not indicated on the label, doctors may prescribe Erythromycin for the slow passage of food from the stomach to the intestine ( Gastroparesis ) and other conditions that involve poor movement of substances through the stomach and intestines.

Erythromycin belongs to the group of drugs known as macrolide antibiotics, which work by preventing bacteria from making the proteins they need to survive and function properly.

Erythromycin was first approved by the Food and Drug Administration (FDA) in 1967 under the Ilosone brand, manufactured by Eli Lilly.

What is Erythromycin used for?

Tablets, capsules, suspension, and Erythromycin injection, are used to treat infections caused by bacteria, such as the following:


  • bacterial infection products of the lungs: Thorax or lower respiratory tract. Examples: bronchitis, bronchiectasis, pneumonia, and legionnaire’s disease.
  • A chronic inflammatory skin disorder of the facial skin: Acne rosacea.
  • Viruses and bacteria: Erythromycin has a similar range of antibacterial activity as penicillin, so it is also helpful as an alternative to penicillin in people allergic to them.
  • Whooping cough: Erythromycin can also be prescribed to prevent this infection in people who have not been vaccinated against pertussis and are in close contact with someone who has it.
  • Bacterial infection of the nasal passages, nasal sinuses, or throat: Upper respiratory tract infection. Examples: sinusitispharyngitis, laryngitis, and tonsillitis.
  • Bacterial infection of the ear: Otitis media or the external auditory canal (otitis externa).
  • Bacterial oral infections: gum disease (gingivitis), Vincent’s angina.
  • Bacterial infection of the eyelids: Blepharitis.
  • Bacterial infections of the skin or soft tissue: boils, abscesses, cellulitis, impetigo, erysipelas.
  • Bacterial infections of the stomach and intestines:  Campylobacter enteritis.
  • Inflammation of the urethra due to bacterial infection: urethritis.
  • Inflammation of the prostate gland due to bacterial infection: prostatitis.
  • Chlamydia .
  • Syphilis.
  • Diphtheria.
  • Scarlet fever.
  • Lyme’s disease.
  • Acne.

Erythromycin can also prevent bacterial infection after surgery, burns, or trauma. It is given by injection to treat more severe infections and in cases where the medication can not be taken orally.

How does Erythromycin work?

Erythromycin is a type of medicine known as a macrolide antibiotic. It works by preventing bacteria from producing proteins that are essential for them. Without these proteins, the bacteria can not grow, replicate and increase in numbers.

Erythromycin does not directly kill bacteria but leaves them unable to increase in numbers. The remaining bacteria eventually die or are destroyed by the immune system. This treats the infection.

This drug is a broad-spectrum antibiotic active against a wide variety of bacteria that cause various infections.

To ensure that the bacteria that cause an infection are susceptible to Erythromycin, your doctor may take a tissue sample, such as a swab from your throat or skin.

Erythromycin is also active against the bacteria associated with acne, Propionibacterium acnes. This common type of bacteria feeds on sebum produced by the sebaceous glands in the skin.

It produces waste products and fatty acids that irritate the sebaceous glands, inflaming them and causing spots. By controlling the number of bacteria, Erythromycin controls the inflammation of the sebaceous glands and allows the skin to heal.

However, other antibiotics for acne may be preferred since the Propionibacterium strains resistant to Erythromycin are becoming widespread.


The dose of Erythromycin prescribed, how often you take it, and how long depend on your type of infection, age, and kidney function.

Erythromycin is usually taken twice daily (every 12 hours) or four times daily (every six hours), depending on the infection type. It would help if you tried to space your doses evenly throughout the day.

Erythromycin can be taken with or without food.

Erythromycin gastro-resistant tablets and capsules should be swallowed whole with a drink and not broken, crushed, or chewed.

Do not take indigestion remedies (antacids) in the two hours before or after taking these forms of Erythromycin.

Erythromycin suspension bottles should be shaken before measuring a dose. Only use the measuring spoon provided with the suspension.

You should not use a regular teaspoon or a large spoonful to administer the medication, as this will not provide an accurate dose.

Unless your doctor tells you otherwise, you must complete the prescribed cycle of Erythromycin, even if you feel better or the infection seems to have cleared up.

Stopping treatment early increases the chances of the infection returning, and the bacteria will become resistant to the antibiotic.

Erythromycin tablets should not be broken in half before administration.

Mild to moderate inflammatory acne:

A thin layer of cream or solution should be applied to the affected areas twice a day for 8-12 weeks.

Severe impetigo, folliculitis, erysipelas, cellulitis and moderate to severe acne:

Adults: 250 mg four times a day for 7-10 days.

Patients with acne should receive 250 mg four times a day for 6-8 weeks, followed by 250 mg twice daily until an improvement occurs. The treatment may need to be continued for up to 6 months.

Children: 30 mg daily in four doses for 7-10 days.

Winks in children under eight years old:

30 mg in four divided doses for 7-10 days.

Side effects

This drug may be responsible for causing nausea, vomiting, diarrhea, pain or stomach cramps, and loss of appetite.

Taking this medicine with food can reduce these symptoms. If any of these effects persist or worsen, inform your doctor promptly.

Serious side effects:

Tell your doctor immediately if you experience severe side effects, including:

  • Persistent nausea/vomiting
  • Yellowish eyes or skin
  • Dark urine.
  • Severe stomach / abdominal pain.
  • Unusual tiredness
  • Muscular weakness.
  • Difficulty speaking.
  • Blurry vision.
  • Fallen eyelids.
  • Hearing loss.
  • Intense dizziness
  • Fainting.
  • Accelerated or irregular heart rhythm.
  • Persistent diarrhea
  • Abdominal or stomach pain or spasms.
  • Blood or mucus in the stool

Considerations: Do not use antidiarrheal products or narcotic analgesics if you have any of these symptoms because these products can make them worse.

This medication for prolonged or repeated periods may cause oral thrush or a new fungal infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

Other side effects:

Medicines and their possible side effects can affect individual people in different ways.

  • Nausea and vomiting.
  • Abdominal pain.
  • Diarrhea.
  • Allergic reactions of the skin include rashes, hives, or itching.
  • Alterations of liver function.
  • Inflammation of the liver (hepatitis).
  • Yellowing of the skin and eyes ( jaundice ).
  • Inflammation of the pancreas ( pancreatitis ).
  • Reversible hearing loss (usually only after large doses).
  • Abnormal heartbeat (arrhythmias)
  • Inflammation of the large intestine ( colitis ).

Prolonged treatment with antibiotics can sometimes cause the overgrowth of other organisms that are not susceptible to the antibiotic, for example, fungi or yeasts such as Candida.

This can sometimes cause infections like canker sores. Tell your doctor if you think you have developed a new infection during or after taking Erythromycin.

Interactions with other medications

It is well known that interactions can change the functioning of medications or increase the risks of those severe side effects.

Some products that can interact with Erythromycin are:

  • The Clindamycin.
  • Dofetilide.
  • Digoxin

Many drugs besides Erythromycin can affect the heart rhythm (QT prolongation), including:

  • Amiodarone
  • Cisapride.
  • Pimozide.
  • Procainamide.
  • Propafenone.
  • Quinidine.
  • Sotalol.

Other medications can affect the removal of Erythromycin from your body, affecting how Erythromycin works. For example:

  • Azole antifungals (such as: itraconazole, ketoconazole).
  • Certain calcium channel blockers (such as diltiazem and verapamil).
  • Certain medications are called anticonvulsants (for example, carbamazepine or phenytoin).
  • Colchicine.

Erythromycin can slow down the removal of other drugs from your body, affecting how it works. Examples of affected medications include:

  • Bromocriptine.
  • Quinupristina.
  • Dalfopristina.
  • Certain Benzodiazepines (such as midazolam, triazolam).
  • Eletriptan.
  • Ergot alkaloids (such as ergotamine, dihydroergotamine).
  • Certain medications to treat erectile dysfunction, ED, or pulmonary hypertension (such as sildenafil and tadalafil).
  • Certain medications are “statins” (such as lovastatin and simvastatin).
  • Vinblastine.

Although most antibiotics are unlikely to affect hormonal birth control, such as the pills, patches, or ring, some antibiotics (such as rifampicin and rifabutin) may decrease their effectiveness.

This medicine may interfere with specific laboratory tests (urinalysis), causing false results. Make sure all your doctors know you are using this medication.

Erythromycin is a commonly prescribed antibiotic medication used to treat infections with bacteria.

Other interactions:

Is it dangerous to take different medications at the same time?

Erythromycin should not be taken by people taking any of the following medications since the combination may cause an increased risk of severe side effects:

  • Amisulpride.
  • Astemizole.
  • Cisapride.
  • Domperidone.
  • Eletriptan.
  • Ergotamine.
  • Dihydroergotamine.
  • Dronedarone.
  • Ivabradine.
  • Lercanidipine.
  • Lomitapide.
  • Mizolastina.
  • Help.
  • Quetiapine.
  • Rilpivirine.
  • Saquinavir.
  • Sertindol.
  • Simeprevir.
  • Simvastatin.
  • Terfenadine.
  • Tolterodine.
  • Vinblastine.

Erythromycin can reduce the breakdown of the medications listed below, which may increase the risk of its side effects.

If you are taking one of these and you are prescribed Erythromycin, tell your doctor or pharmacist if you have new or increased side effects:

  • Alfentanil.
  • Alprazolam.
  • Axitinib.
  • Avanafil
  • Bedaquilina.
  • Discarded.
  • Bromocriptine.
  • Buspirone.
  • Carolina.
  • Caboose.
  • Carbamazepine
  • Cyclosporine.
  • Cilostazol.
  • Clozapine.
  • Colchicine.
  • Dapoxetina.
  • Darifenacin.
  • Galantamine.
  • Ibrutinib.
  • Ivacaftor.
  • Lurasidone.
  • Methylprednisolone and possibly other corticosteroids.
  • Midazolam.
  • Phenytoin
  • Pravastatin
  • Quetiapine.
  • Reboxetine.
  • Rifabutin.
  • Rupatadine.
  • Sildenafil.
  • Sirolimus.
  • Tacrolimus.
  • Tadalafil.
  • Dasatinib.
  • Digoxin
  • Disopyramide.
  • Eplerenone.
  • Everolimus.
  • Felodipine.
  • Galantamine.
  • Ibrutinib.
  • Ivacaftor.
  • Lurasidone.

Taking Erythromycin with cholesterol-lowering drugs known as statins, such as Atorvastatin and Lovastatin, increases the risk of muscle side effects (myopathy).

The following medications may increase the level of Erythromycin in the blood, which may increase the risk of its side effects:

  • Cimetidine
  • Protease inhibitors for HIV infection include ritonavir, lopinavir, saquinavir, and amprenavir.

There may be an increased risk of an abnormal heartbeat if you take Erythromycin in combination with any of the following medications (this is less likely with oral Erythromycin than with Erythromycin administered by injection):

  • Amiodarone
  • Arsenic trioxide.
  • Atomoxetine.
  • Certain antimalarials include chloroquine, quinine, mefloquine, and halofantrine.
  • Certain antipsychotics include chlorpromazine, thioridazine, fluphenazine, and haloperidol.
  • Citalopram.
  • Delamanid.
  • Disopyramide.

The oral vaccine against typhoid fever (Vivotif) should not be taken until at least three days after a cycle of Erythromycin since the antibiotic could make this vaccine less effective.

This antibiotic does not affect the contraceptive pill. The old advice has now changed. Using an additional contraceptive method with the pill, patch, or vaginal ring is no longer necessary while taking antibiotic treatment.

This is because, to date, there is no evidence to show that antibiotics (other than Rifampicin or Rifabutin) affect these contraceptives.

However, suppose you are taking the contraceptive pill, and you experience vomiting or diarrhea due to taking this antibiotic. In that case, you should follow the instructions for vomiting and diarrhea described in the brochure provided with the pills.

You should not take Erythromycin if you are taking the following medications:

  • Mevacor (lovastatin).
  • Zocor (simvastatin).
  • Orap (pimozide).

If possible, ask your doctor about other antibiotics you can take instead of Erythromycin if you are taking any of the following:

  • Drugs for irregular heartbeats, such as Betapace or Betapace AF (sotalol), procainamide, Covert (ibutilide), and (Norpace) disopyramide.
  • Arsenic trioxide.
  • Quinidine.
  • Migranal (ergotamine).
  • Diflucan (fluconazole).
  • Indapamide.
  • Drugs for HIV / AIDS, such as Sustiva (efavirenz) and Lexiva (fosamprenavir).
  • Birth control and hormone replacement therapy that contains any form of estrogen.

Erythromycin interacts with many more medications than those listed here, so talk with your pharmacist or doctor before taking Erythromycin.

Erythromycin and Alcohol:

There are no specific warnings about alcohol consumption while taking Erythromycin, but there is some evidence that alcohol can cause delayed antibiotic absorption.

Therefore, you should talk with your doctor about avoiding or limiting alcohol consumption while taking Erythromycin.

Erythromycin and grapefruit juice:

You should avoid eating grapefruit and drinking grapefruit juice while taking Erythromycin.

Grapefruit juice slows down how quickly the body can break down Erythromycin, which could cause levels of Erythromycin in the blood to rise dangerously.

This could be life-threatening because Erythromycin can change the heart rate and electrical activity in the heart.


Erythromycin should be used with caution in:

  1. People with liver or kidney problems.
  2. People with an abnormal heart rhythm are seen on a follow-up cardiac control (ECG) as a “prolonged QT interval.”
  3. People with a condition called myasthenia gravis in which there is abnormal muscle weakness.

Neither should Erythromycin be taken if you:

  1. This is allergic or any of its inactive ingredients.
  2. You are taking medications that can change the electrical activity in the heart.
  3. Has an irregular heart rhythm, including ventricular arrhythmia.
  4. You have liver disease.


Taking Erythromycin for an extended period can increase your chances of developing infections caused by bacteria or fungi that are much more difficult to treat.

Erythromycin can cause live bacterial vaccines (such as the typhoid vaccine) not to work either. Do not get vaccinated/vaccinated while using this medicine unless your doctor tells you to.

Some Erythromycin products may contain sodium. Ask your doctor or pharmacist for more information if you are on a salt-restricted diet or have a condition such as congestive heart failure that could be made worse by an increase in salt intake.

Older adults may be more sensitive to the side effects of Erythromycin, especially hearing loss and prolongation of the QT interval.

Important considerations about Erythromycin

Broad-spectrum antibiotics can sometimes cause inflammation of the intestine (colitis). For this reason, you should consult your doctor immediately if you have diarrhea that becomes severe or persistent or contains blood or mucus during or after taking Erythromycin.

Who should not take Erythromycin?

Erythromycin should be used with caution in:

  • People with liver or kidney problems.
  • People with a condition called myasthenia gravis in which there is abnormal muscle weakness.
  • People with hereditary blood disorders are called porphyrias.

Can I take Erythromycin while I am pregnant or in the process of breastfeeding?

Erythromycin is not harmful when used during pregnancy. However, it passes into breast milk in small amounts.

It is not known to be harmful to the infant. However, you should inform your doctor if you think your baby has developed diarrhea, thrush, or rash in diapers if you are breastfeeding while taking Erythromycin.

Ophthalmic solution:

You should not use Erythromycin if you are allergic to it or have a viral or fungal infection in your eye. You should know that this medication is only used to treat infections caused by bacteria.

Important consideration: Do not let the tip of the tube touch any surface, even with your eyes or hands. Well, if the tip becomes contaminated, it could cause an eye infection, which can cause vision loss or other severe damage to the eye.

Note: Your symptoms may improve before the infection completely disappears, but you must use this medication for the entire prescribed time.

Ophthalmic Erythromycin can cause blurred vision. Be careful if you drive or do anything that requires seeing clearly.

Do not use other eye medications during treatment with Erythromycin ophthalmic unless your doctor tells you to.

Overdose of Erythromycin:

Contact a poison control center or emergency room if you suspect an overdose.

Missed a dose of Erythromycin?:

If you miss a dose, try to take it as soon as you remember. However, if it is almost time for the next dose, skip it and resume your regular dosing schedule. Do not duplicate it to compensate for the forgotten dose.


  • Keep in a room at room temperature, away from light and moisture.
  • Do not store it in the bathroom.
  • Keep all medications out of the reach of children and pets.
  • Do not throw medicines into the toilet or pour them into the drain unless instructed.
  • Discard this product correctly when it has expired or is no longer necessary.