Last Updated: February 2026 | Reviewed by Dr. Davinder Sidhu, OD
Erythromycin Eye Ointment
Erythromycin eye ointment is a widely used prescription antibiotic ointment for treating bacterial eye infections. As a macrolide antibiotic, it works by stopping the growth of bacteria, making it effective against a range of common eye infections including bacterial conjunctivitis (pink eye).
In this guide, we'll cover everything you need to know about erythromycin eye ointment, including its uses, how to apply it properly, potential side effects, dosage information, and storage guidelines.
What Is Erythromycin Eye Ointment?
Erythromycin ophthalmic ointment is a macrolide antibiotic applied directly to the eye to treat bacterial infections. It contains erythromycin 0.5% in a sterile ophthalmic base.
Erythromycin works by binding to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and preventing bacterial growth and reproduction.
Uses for Erythromycin Eye Ointment
Erythromycin eye ointment is commonly prescribed for:
- Bacterial conjunctivitis (pink eye): One of the most common uses, particularly effective against gram-positive bacteria.
- Neonatal conjunctivitis prophylaxis: Routinely applied to newborns' eyes shortly after birth to prevent ophthalmia neonatorum.
- Blepharitis: Bacterial infection of the eyelids.
- Corneal ulcers: Bacterial infections of the cornea (in some cases).
- Other superficial bacterial eye infections: As determined by your eye care professional.
How to Apply Erythromycin Eye Ointment
Proper application is important for effectiveness:
- Wash your hands thoroughly before use.
- Tilt your head back and pull down your lower eyelid to create a small pocket.
- Hold the tube close to your eye (without touching it).
- Squeeze a thin strip (approximately 1 cm) of ointment into the pocket formed by the lower eyelid.
- Close your eye gently and roll your eyeball in all directions to spread the ointment.
- Keep your eye closed for 1 to 2 minutes.
- Wipe away any excess ointment from around the eye with a clean tissue.
- Replace the cap on the tube immediately after use.
Note: Erythromycin ointment will cause temporary blurred vision after application. Avoid driving or operating machinery until your vision clears.
Dosage
The typical dosage for erythromycin eye ointment is:
- Bacterial conjunctivitis: Apply a 1 cm strip to the affected eye(s) up to 6 times daily, depending on the severity of the infection.
- Neonatal prophylaxis: A single application of a 1 cm strip to each eye shortly after birth.
- General infections: Typically 2 to 4 times daily as directed by your doctor.
Continue using the ointment for the full duration prescribed by your doctor, even if symptoms improve before the course is complete. Stopping early can allow bacteria to continue growing, potentially leading to a return of the infection.
Side Effects
Erythromycin eye ointment is generally well-tolerated, but some side effects may occur:
Common side effects:
- Temporary blurred vision after application
- Mild stinging or burning sensation
- Minor eye irritation
Less common side effects:
- Eye redness
- Allergic reaction (rash, itching, swelling)
- Sensitivity to light
If you experience severe or persistent side effects, contact your eye care professional promptly.
Precautions
- Do not use erythromycin eye ointment if you are allergic to erythromycin or any macrolide antibiotics.
- Inform your doctor about all other medications you are using, including other eye drops or ointments.
- If using multiple eye medications, wait at least 10 minutes between applications. Apply ointments last.
- Do not wear contact lenses while using this ointment unless directed by your doctor.
- Keep the tube tip sterile. Do not touch it to your eye, fingers, or any other surface.
Storage
Proper storage helps maintain the effectiveness of erythromycin eye ointment:
- Store at room temperature, away from heat and direct light.
- Do not freeze.
- Keep the tube tightly closed when not in use.
- Discard the tube after the expiry date or as directed by your pharmacist.
- Keep out of reach of children.
Erythromycin Eye Ointment for Pets
Erythromycin eye ointment is sometimes prescribed by veterinarians for treating bacterial eye infections in cats and dogs. However, never use a human prescription on a pet without veterinary guidance. Dosage and frequency may differ, and some formulations may contain ingredients that are not safe for animals.
Always consult your veterinarian if you suspect your pet has an eye infection.
Frequently Asked Questions
Is erythromycin eye ointment available over the counter?
In Canada, erythromycin eye ointment is available by prescription only. You will need to see a doctor or eye care professional to obtain it.
How long does it take for erythromycin eye ointment to work?
Most people begin to notice improvement within 1 to 2 days of starting treatment. However, it's important to complete the full course of treatment as prescribed, which is typically 5 to 7 days.
Can erythromycin eye ointment be used for viral pink eye?
No, erythromycin is an antibiotic that only works against bacterial infections. It will not be effective against viral conjunctivitis. Your doctor will determine whether your infection is bacterial or viral before prescribing treatment.
Can I use erythromycin eye ointment while pregnant?
Erythromycin eye ointment is generally considered safe during pregnancy, as minimal amounts are absorbed systemically. However, always consult your doctor before using any medication during pregnancy.
What should I do if I miss a dose?
Apply the missed dose as soon as you remember. If it's almost time for your next dose, skip the missed one and continue with your regular schedule. Do not apply extra ointment to make up for a missed dose.
Final Thoughts
Erythromycin eye ointment remains a trusted and effective treatment for bacterial eye infections. Its long track record of safety, including its routine use in newborns, makes it a reliable choice for many patients. As with any prescription medication, follow your doctor's instructions carefully and complete the full course of treatment for the best results.
If you have questions about erythromycin or any other eye care products, consult your eye care professional for personalized advice.
About the Reviewer
Dr. Davinder Sidhu is an optometrist based in British Columbia with a focus on dry eye management and preservative-free solutions. Learn more at TheGenuwineOD.com or follow him on Instagram and Facebook.
