Azithromycin (EENT) (Monograph)

Brand name: AzaSite
Drug class: Antibacterials

Introduction

Macrolide antimicrobial.

Uses for Azithromycin (EENT)

Bacterial Conjunctivitis

Topical treatment of bacterial conjunctivitis caused by susceptible CDC coryneform group G (efficacy for this organism studied in <10 infections), Haemophilus influenzae, Staphylococcus aureus, Streptococcus mitis group, and Streptococcus pneumoniae.

Mild, acute bacterial conjunctivitis often resolves spontaneously without anti-infective therapy. Although topical ophthalmic anti-infectives may shorten time to resolution and reduce severity and risk of complications, avoid indiscriminate use of topical anti-infectives. Treatment of acute bacterial conjunctivitis generally is empiric; use of a broad-spectrum topical ophthalmic antibacterial usually is recommended. In vitro staining and/or cultures of conjunctival material may be indicated in management of recurrent, severe, or chronic purulent conjunctivitis or when acute conjunctivitis does not respond to initial empiric topical treatment.

Azithromycin (EENT) Dosage and Administration

General

Patient Monitoring

Monitor for the emergence of resistant infections. As with other anti-infectives, prolonged use may result in overgrowth of non-susceptible organisms.

Dispensing and Administration Precautions

For topical ophthalmic use only; do not administer systemically, inject subconjunctivally, or introduce directly into anterior chamber of eye.
Avoid contaminating the applicator tip by not allowing it to touch the eye, fingers, or other sources.
Avoid wearing contact lenses if experiencing symptoms of bacterial conjunctivitis and during treatment.

Administration

Apply topically to the affected eye(s).

Ophthalmic Administration

Available as 2.5 mL of a 1% sterile topical ophthalmic solution.

For topical ophthalmic use only.

Wash hands prior to administration. Invert the closed bottle (upside down) and shake once before each use. Remove the cap with the bottle still in the inverted position. Tilt head back, and with bottle inverted, gently squeeze to instill one drop into the affected eye(s).

Skipping doses or not completing the full course of therapy may decrease the effectiveness of the immediate treatment and increase the likelihood that bacteria will develop resistance and will not be treatable by azithromycin or other antibacterials in the future.

Dosage

Pediatric Patients

Bacterial Conjunctivitis

Ophthalmic

1 drop in the affected eye(s) twice daily, 8–12 hours apart, for the first 2 days, then 1 drop once daily for the next 5 days.

Clinical studies evaluated pediatric patients ≥1 year of age.

Adults

Bacterial Conjunctivitis

Ophthalmic

1 drop in the affected eye(s) twice daily, 8–12 hours apart, for the first 2 days, then 1 drop once daily for the next 5 days.

Special Populations

Hepatic Impairment

No special population dosage recommendations at this time.

Renal Impairment

No special population dosage recommendations at this time.

Geriatric Patients

No special population dosage recommendations at this time.

Cautions for Azithromycin (EENT)

Contraindications

Hypersensitivity to any component.

Warnings/Precautions

Administration Precautions

For topical ophthalmic use only. Do not administer systemically, inject subconjunctivally, or introduce directly into the anterior chamber of the eye.

Avoid contaminating the applicator tip by not allowing it to touch the eye, fingers, or other sources.

Sensitivity Reactions

Serious and occasionally fatal hypersensitivity and/or anaphylactic reactions including angioedema, anaphylaxis, and dermatologic reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis have been reported in patients receiving systemic azithromycin. The potential for anaphylaxis or other hypersensitivity reactions should be considered based on known hypersensitivity to azithromycin when administered systemically.

Growth of Resistant Organisms with Prolonged Use

As with other anti-infectives, prolonged use may result in overgrowth of non-susceptible organisms, including fungi.

Avoidance of Contact Lenses

Advise patients not to wear contact lenses if they have signs or symptoms of bacterial conjunctivitis.

Specific Populations

Pregnancy

Data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes.

Lactation

Present in human milk. Non-serious adverse reactions reported in breastfed infants after maternal administration of oral azithromycin. No data on the effects of azithromycin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for azithromycin and any potential adverse events on the breastfed infant.

Pediatric Use

Not established in pediatric patients ≤1 year of age.

Geriatric Use

No differences in safety or efficacy observed between geriatric patients ≥65 years of age and younger adults (<65 years of age).

Common Adverse Effects

Most common adverse reactions (1–2%): eye irritation.

Drug Interactions

Specific drug interaction studies not performed. Systemic exposure following ocular administration not known, but is estimated to be minimal.

Azithromycin (EENT) Pharmacokinetics

Absorption

Bioavailability

Systemic absorption following topical ophthalmic administration unknown. Plasma concentrations following ocular administration estimated to be below quantifiable limits (<10 ng/mL) at steady-state.

Stability

Storage

Ophthalmic

Solution

Store unopened bottles in refrigerator at 2–8ºC.

Once opened, store bottles at 2–25ºC for up to 14 days. Discard after 14 days.

Actions

Macrolide antimicrobial.
Binds to the 50S ribosomal subunit of susceptible microorganisms and interferes with microbial protein synthesis.
In vitro and clinically, activity demonstrated against CDC coryneform group G (efficacy for this organism was studied in fewer than 10 infections), Haemophilus influenzae, Staphylococcus aureus, Streptococcus mitis group,and Streptococcus pneumoniae.
In vitro, activity demonstrated against Chlamydia pneumoniae, Chlamydia trachomatis, Legionella pneumophila, Moraxella catarrhalis, Mycoplasma hominis, Mycoplasma pneumoniae, Neisseria gonorrhoeae, Peptostreptococcus species, Streptococci (Groups C, F, G), Streptococcus pyogenes, Streptococcus agalactiae, Ureaplasma urealyticum, and Viridans group streptococci; clinical activity in ophthalmic infections has not been demonstrated.

Advice to Patients

Advise patients to review FDA-Approved Patient Labeling (Patient Information and Instructions for Use).
Advise patients to avoid contaminating the applicator tip by not allowing it to touch the eye, fingers, or other sources.
Direct patients to discontinue use and contact a physician if any signs of an allergic reaction occur.
Inform patients that although it is common to feel better early in the course of the therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by azithromycin ophthalmic solution or other antibacterial drugs in the future.
Advise patients not to wear contact lenses if they have signs or symptoms of bacterial conjunctivitis.
Advise patients to thoroughly wash hands prior to using azithromycin.
Advise patients to invert the closed bottle (upside down) and shake once before each use. Remove cap with bottle still in the inverted position. Tilt head back, and with bottle inverted, gently squeeze to instill one drop into the affected eye(s).
Advise patients to inform their clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses.
Advise patients to inform their clinician if they are or plan to become pregnant or plan to breast-feed.
Inform patients of other important precautionary information.

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.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.