Drug class: Antibacterials

Medically reviewed by Drugs.com on Sep 10, 2024. Written by ASHP.

Introduction

Antibacterial; macrolide antibiotic.^{139 140}

Uses for Erythromycin (EENT)

Bacterial Ophthalmic Infections

Topical treatment of superficial infections of the eye involving the conjunctiva and/or cornea caused by susceptible bacteria.^{139 140}

Mild, acute bacterial conjunctivitis often resolves spontaneously without anti-infective treatment.^{135 136 137 141} Although topical ophthalmic anti-infectives may shorten time to resolution and reduce severity and risk of complications,^{135 136 137 141} avoid indiscriminate use of topical anti-infectives.^{135 141}

Treatment of acute bacterial conjunctivitis generally is empiric;^{135 136 141} use of a broad-spectrum topical ophthalmic antibacterial usually recommended.^{135 136 141} In vitro staining and/or cultures of conjunctival material indicated in diagnosis and management of all cases of suspected infectious conjunctivitis in neonates,^{135 136 141 292 344} all cases of suspected gonococcal or chlamydial conjunctivitis,^{292 344} and may be indicated in management of recurrent, severe, or chronic purulent conjunctivitis or when acute conjunctivitis does not respond to initial empiric topical treatment.^{135 136 141}

Bacterial conjunctivitis caused by Neisseria gonorrhoeae requires treatment with systemic anti-infectives (e.g., IM or IV ceftriaxone)^{135 136 141 292 344} with or without topical anti-infectives.^{135 136 141} Topical anti-infectives alone are inadequate for treatment of ophthalmia neonatorum caused by N. gonorrhoeae;²⁹² some experts state that adjunctive use of topical anti-infectives unnecessary when appropriate systemic anti-infectives used.²⁹²

Chlamydial Ophthalmic Infections

Has been used topically in the treatment of conjunctivitis secondary to trachoma caused by Chlamydia trachomatis ^{† [off-label]};^{127 128 129 130 131 134 136} however, systemic anti-infectives (usually oral azithromycin) are recommended for treatment of ocular trachoma.^{136 292}

Systemic anti-infectives (e.g., oral azithromycin, doxycycline, or erythromycin) are necessary for treatment of chlamydial conjunctivitis, including chlamydial ophthalmia neonatorum.^{135 136 292 344} Experts state that topical anti-infectives alone are inadequate for treatment of chlamydial ophthalmic infections and are unnecessary when appropriate systemic anti-infectives used.^{292 344}

Has been used for topical prophylaxis of ophthalmia neonatorum caused by C. trachomatis.^{139 140} However, efficacy of topical prophylaxis for prevention of chlamydial neonatal conjunctivitis not established.^{101 102 103 104 106 107 109 114 116 292 344} Experts state that erythromycin used for topical prophylaxis of gonococcal ophthalmia neonatorum will not prevent chlamydial ophthalmia neonatorum.²⁹²

Prophylaxis of Gonococcal Ophthalmia Neonatorum

Topical prophylaxis of ophthalmia neonatorum caused by N. gonorrhoeae.^{139 140 292 344} Efficacy for prevention of ophthalmia neonatorum caused by penicillinase-producing N. gonorrhoeae not established.^{139 140}

CDC and AAP recommend topical erythromycin prophylaxis in all neonates as soon as possible after birth (regardless of whether they are delivered vaginally or by cesarean section);^{292 344} such prophylaxis required by law in most states.^{292 344} Although silver nitrate and tetracycline have been used in the past for topical prophylaxis of gonococcal ophthalmia neonatorum, ophthalmic preparations of these drugs no longer commercially available in the US.^{292 344}

If erythromycin ophthalmic ointment not available, CDC recommends systemic prophylaxis with a single dose of ceftriaxone (IM or IV) for all neonates at risk for exposure to N. gonorrhoeae (especially those born to women who are at risk for gonococcal infection or received no prenatal care).³⁴⁴

Infants born to women with untreated gonorrhea are at high risk of infection; CDC and AAP recommend that such neonates receive systemic prophylaxis with a single dose of ceftriaxone (IM or IV) instead of topical erythromycin prophylaxis.^{292 344}

Erythromycin (EENT) Dosage and Administration

Administration

Ophthalmic Administration

Apply 0.5% ophthalmic ointment topically to the eye.^{139 140}

For topical ophthalmic use only.^{139 140}

Avoid contaminating tip of ointment tube with material from eye, fingers, or other source.^{139 140}

When used for prophylaxis of gonococcal ophthalmia neonatorum, place specified amount of ointment into each of neonate’s lower conjunctival sacs^{139 140} and massage gently to spread ointment;²⁹² after 1 minute, wipe away excess ointment with sterile cotton.²⁹² Do not flush ointment from the eye following application.^{139 140 292} Use a new tube or single-use container of ointment for each neonate.^{139 140}

Dosage

Pediatric Patients

Bacterial Ophthalmic Infections

Ophthalmic

Apply 1-cm ribbon of 0.5% ointment to the affected eye(s) up to 6 times daily.^{139 140} For empiric treatment of acute bacterial conjunctivitis, experts recommend application 4 times daily for 1 week.¹³⁶

Prophylaxis of Gonococcal Ophthalmia Neonatorum

Ophthalmic

Place 1-cm ribbon of 0.5% ointment into lower conjunctival sac of both eyes.^{139 140}

Administer as soon as possible (within 1 hour) after birth.^{292 344} Efficacy unlikely to be affected if topical prophylaxis delayed for up to 1 hour after delivery (e.g., to facilitate parent-infant bonding);²⁹² efficacy of prophylaxis administered after a longer delay not studied.²⁹²

Adults

Bacterial Ophthalmic Infections

Ophthalmic

Apply 1-cm ribbon of 0.5% ointment to the affected eye(s) up to 6 times daily.^{139 140} For empiric treatment of acute bacterial conjunctivitis, experts recommend application 4 times daily for 1 week.¹³⁶

Cautions for Erythromycin (EENT)

Contraindications

• Hypersensitivity to erythromycin.^{139 140}

Warnings/Precautions

Sensitivity Reactions

Hypersensitivity

Possible sensitivity reactions.^{139 140}

General Precautions

Superinfection

Prolonged use may result in overgrowth of nonsusceptible organisms, including fungi.^{139 140}

If superinfection occurs, discontinue and institute appropriate therapy.^{139 140}

Specific Populations

Pregnancy

Data not available regarding use in pregnant women.^{139 140} Use only if clearly needed.^{139 140}

Lactation

Use with caution in nursing women.^{139 140}

Pediatric Use

See Uses.

Geriatric Use

No overall differences in safety or efficacy compared with younger patients.¹⁴⁰

Common Adverse Effects

Minor ocular irritation, redness, hypersensitivity.^{139 140}

Erythromycin (EENT) Pharmacokinetics

Absorption

Extent

Topical application to the eye probably does not produce significant antibacterial concentrations in deep layers of cornea or in aqueous humor.^a

Not known whether erythromycin is absorbed to any substantial extent from mucous membranes.^a

Stability

Storage

Ophthalmic

Ointment

15–25°C.^{139 140}

Do not expose to excessive heat;¹⁴⁰ do not freeze.¹⁴⁰

Actions and Spectrum

• Usually bacteriostatic; may be bactericidal in high concentrations or against highly susceptible organisms.^a

• Inhibits protein synthesis in susceptible organisms by binding to 50S ribosomal subunits.^a

• Gram-positive bacteria: Active in vitro and in clinical infections against Staphylococcus aureus (methicillin-susceptible strains only), Streptococcus pneumoniae, S. pyogenes (group A β-hemolytic streptococci; GAS), viridans streptococci (α-hemolytic streptococci), and Corynebacterium diphtheriae.^{139 140}

• Gram-negative bacteria: Active in vitro and in clinical infections against some strains of Haemophilus influenzae and Neisseria gonorrhoeae.^{139 140}

• Active against Chlamydia trachomatis and Mycoplasma pneumoniae.^{139 140} Also has activity against Treponema pallidum.^{139 140}

Advice to Patients

• Advise patients to avoid contaminating tip of ointment tube with material from the eye, fingers, or other source.^{139 140}

• Advise patients to immediately discontinue erythromycin ophthalmic ointment and contact a clinician at first sign of hypersensitivity reaction.^{139 140}

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.^{139 140}

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.^{139 140}

• Importance of informing patients of other important precautionary information. (See Cautions.)^{139 140}

Additional Information

The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer’s labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.

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