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Erythromycin

Common Brand Names: Erythrocin, EES, Ilosone

Drug Information

Medically reviewed by Jessica Swirble, PharmD
Last updated on March 26, 2025

Drug Information | Side Effects | Use & Dosage | Request an Online Prescription

Quick Facts

  • Brand Name: ERY-C, Ery-Tab, Erythrocin, PCE
  • Generic Name: Erythromycin
  • Uses: Treatment for bacterial infections
  • Drug Class: Macrolide antibiotic
  • Availability: Prescription and over-the-counter
  • Generic Status: Yes
  • Controlled Substance: No

What is erythromycin?

Erythromycin is an antibiotic medication used to treat bacterial infections in various areas of the body.

What conditions does erythromycin treat?

Erythromycin is prescribed for the treatment of various bacterial infections, including:

  • Respiratory tract infections such as pneumonia and bronchitis
  • Skin infections like cellulitis and impetigo
  • Ear infections
  • Eye infections
  • Sexually transmitted infections like chlamydia, gonorrhea, and syphilis
  • Legionnaires' disease
  • Pertussis (whooping cough)
  • Prevention of recurrent rheumatic fever
  • Dental infections

How does erythromycin work?

Erythromycin works by inhibiting the growth of bacteria. It does this by interfering with their protein synthesis, ultimately leading to the death of the bacteria.

How do I take erythromycin?

Erythromycin is available as an oral tablet, capsule, delayed-release capsule, and liquid suspension. It may also be available in ointment and topical gel forms for certain skin conditions. Ophthalmic erythromycin is used for the treatment of bacterial eye infections. The form of erythromycin prescribed will depend on the infection requiring treatment.

How long until I feel better?

The time it takes to notice an improvement in symptoms can vary depending on the type of infection being treated. It's essential to complete the full course of treatment as prescribed by your healthcare provider, even if you start feeling better before the medication is finished.

Are there other uses for erythromycin?

Erythromycin may also be prescribed off-label for conditions such as acne. It may also be prescribed to prevent heart infections in patients undergoing dental surgery or other procedures. Discuss any alternative uses with your healthcare provider.

Dosage forms of erythromycin

Erythromycin is available as an oral tablet, capsule, delayed-release capsule, and liquid suspension. It may also be available in ointment and topical gel forms. Ophthalmic erythromycin is available for bacterial eye infections.

Erythromycin is available under brand names like ERY-C, Ery-Tab, Erythrocin, and PCE. Generic versions of erythromycin are also available.

Erythromycin is available both over-the-counter and via prescription. For systemic infections, you must have a written prescription from a licensed healthcare provider to obtain this medication.

Side Effects and Precautions for Erythromycin


Drug Information | Side Effects | Use & Dosage | Request an Online Prescription

What are the side effects of erythromycin?

The use of erythromycin has been shown to cause side effects in some patients.

Common mild side effects of erythromycin use include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Loss of appetite
  • Skin rash or itching
  • Dizziness
  • Headache
  • For opthalmic erythromycin: eye irritation (redness, burning, or stinging around the eye)

More severe side effects include:

  • Severe abdominal pain
  • Yellowing of the skin or eyes (jaundice)
  • Dark urine
  • Unusual fatigue
  • Irregular heartbeat
  • Muscle weakness
  • Difficulty breathing or swallowing
  • Swelling of the face, lips, tongue, or throat
  • Severe diarrhea

Seek medical attention immediately if you experience any severe symptoms while taking erythromycin. If you experience mild side effects that become severe or do not go away after a few days, speak to a healthcare provider right away.

What should I tell my healthcare provider before using erythromycin?

Tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with erythromycin. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with this drug.

Tell your provider if you are taking these medications or supplements:

  • Warfarin or other blood thinners
  • Digoxin or other heart medications
  • Theophylline or other asthma medications
  • Ergotamine or other migraine medications
  • Birth control pills
  • Statin medications
  • Benzodiazepines
  • Calcium channel blockers
  • Colchicine

You should also mention medical conditions such as:

  • Liver disease
  • Kidney disease
  • Heart rhythm disorders
  • Myasthenia gravis
  • Long QT syndrome

If you are pregnant, planning to become pregnant, or breastfeeding, consult your healthcare provider before using erythromycin to assess potential risks and benefits.

Are there any other special instructions I should follow?

You can follow your regular diet while taking erythromycin. However, until you know how erythromycin affects you, avoid activities requiring mental alertness, such as driving or operating heavy machinery. Erythromycin may cause dizziness or lightheadedness.

Avoid eating grapefruit or drinking grapefruit while taking erythromycin. Grapefruit can increase the effects of erythromycin, leading to more side effects.

Avoid consuming alcohol while taking erythromycin, as it may increase the risk of side effects such as stomach upset and liver toxicity.

Your healthcare provider will provide specific instructions regarding the use of erythromycin with food, beverages, and other medications. It's essential to follow their guidance to ensure the effectiveness of the treatment and minimize the risk of side effects.

What should I do in case of an overdose?

If you suspect an overdose of Erythromycin or experience severe symptoms, seek immediate medical attention or contact a poison control center. Symptoms of an overdose may include nausea, vomiting, diarrhea, and abdominal pain. If an individual has collapsed, is having seizures, or is unresponsive, call 9-1-1 immediately.

Proper Use & Dosage Information for Erythromycin


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What is the typical starting dose for erythromycin?

Erythromycin is available in various forms:

  • Oral tablets (250 mg)
  • Oral capsules (250 mg, 333 mg, 400 mg, 500 mg)
  • Oral suspension (200 mg/5 ml, 400 mg/5 ml)
  • Topical formulations (2% gel or solution)

The typical starting dose of erythromycin can vary depending on the type and severity of the infection, the age of the patient, and other medical considerations. It is important to strictly follow your healthcare provider's instructions regarding dosage and administration.

For adults with mild to moderate infections treated orally, the typical starting doses may be:

  • 400-800 mg every 6 to 12 hours or as prescribed by your doctor.

For children, the typical starting doses may be based on weight and age, usually ranging from:

  • 30 to 50 mg/kg/day divided into 4 doses.

For topical erythromycin used to treat acne or skin infections, the typical starting dose may involve applying a thin layer of the cream, gel, or ointment to the affected area once or twice daily.

Your healthcare provider will evaluate your medical condition, allergies, and other medications you may be taking to determine the most appropriate dose and formulation for you.

Erythromycin should be taken or applied exactly as directed by your healthcare provider. Do not exceed the recommended dose or duration of treatment without consulting your doctor.

If you have any questions about your dosage, contact your healthcare provider. If you want to talk to a provider right away, book an online doctor appointment on Sesame to discuss your concerns.

What should I do if I miss a dose?

If you miss a dose, take it as soon as you remember it. If it's almost time for another dose of erythromycin, skip the missed dose and take your next dose as scheduled. Do not take or apply a double dose of erythromycin.

What do I do if I'm feeling better?

Do not discontinue or alter your erythromycin dosage without consulting with your healthcare provider. Follow your healthcare provider's instructions regarding dosing and other recommendations for taking erythromycin.

How should I store erythromycin?

Store erythromycin as directed by your healthcare provider or pharmacist. Proper storage is essential to maintain the medication's effectiveness. Erythromycin should be stored at room temperature, away from excessive heat, light, and moisture.

Keep the medication out of the reach of children and ensure that the container is tightly closed.

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