Neomycin is an aminoglycoside antibiotic.
Bacterial Ophthalmic Infections
Neomycin is used in fixed combination with other anti-infectives (i.e., polymyxin B sulfate and bacitracin zinc; polymyxin B and gramicidin) for the topical treatment of superficial infections of the eye (e.g., conjunctivitis, keratitis, keratoconjunctivitis, blepharitis, blepharoconjunctivitis) caused by susceptible bacteria.105, 106, 125, 126
Fixed-combination topical ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and bacitracin zinc are considered active against Staphylococcus aureus , streptococci (including Streptococcus pneumoniae ), Escherichia coli , Haemophilus influenzae , Enterobacter , Klebsiella , Neisseria , and Pseudomonas aeruginosa , but do not provide adequate coverage against Serratia marcescens .105, 106
Fixed-combination topical ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and gramicidin are considered active against S. pneumoniae , E. coli , H. influenzae , Enterobacter , Klebsiella , Neisseria , and Ps. aeruginosa , but do not provide adequate coverage against S. marcescens .125, 126
Although mild, acute bacterial conjunctivitis often resolves spontaneously without anti-infective treatment,135, 136, 137, 141 topical ophthalmic anti-infectives may shorten the time to resolution and reduce severity and risk of complications.135, 136, 137, 141 Treatment of acute bacterial conjunctivitis generally is empiric and use of a broad-spectrum topical ophthalmic antibacterial usually is recommended;135, 136, 141 however, indiscriminate use of topical anti-infectives should be avoided.135, 141 In vitro staining and/or cultures of conjunctival material may be indicated in the management of recurrent, severe, or chronic purulent conjunctivitis or when acute conjunctivitis does not respond to initial empiric topical treatment.135, 136, 141
Because many forms of bacterial keratitis are associated with subsequent loss of vision as the result of corneal scarring or topographic irregularities and because untreated or severe bacterial keratitis may result in perforation of the cornea with the potential for endophthalmitis and possible loss of the eye, optimal management involves rapid evaluation and diagnosis, timely initiation of treatment, and appropriate follow-up.138 Treatment of community-acquired bacterial keratitis generally is empiric and use of a broad-spectrum topical ophthalmic antibacterial usually is recommended.138 Subconjunctival therapy with an appropriate anti-infective may be necessary if scleral spread or perforation is imminent.138 In vitro staining and/or cultures are indicated in the management of keratitis involving corneal infiltrates that are central, large, and extending to the middle to deep stroma; when keratitis is chronic or unresponsive to broad-spectrum topical anti-infective treatment; or when atypical features are present suggesting fungal, amebic, or mycobacterial infection.138
Neomycin is used in fixed combination with colistin and hydrocortisone acetate or in fixed combination with polymyxin B sulfate and hydrocortisone for the topical treatment of superficial infections of the external auditory canal (otitis externa) caused by susceptible bacteria.109, 110, 121, 122, 123, 124, 139 These fixed-combination otic preparations also are used for the topical treatment of infections of mastoidectomy or fenestration cavities caused by susceptible bacteria.109, 110, 121, 124
Diffuse, uncomplicated acute otitis externa in otherwise healthy patients usually should be treated initially with topical therapy (e.g., otic anti-infective or antiseptic with or without an otic corticosteroid).139, 143 Topical therapy should be supplemented with systemic anti-infective therapy if the patient has a medical condition that could impair host defenses (e.g., diabetes mellitus, human immunodeficiency virus [HIV] infection) or if the infection has spread into the pinna, skin of the neck or face, or into deeper tissues such as occurs with malignant otitis externa.139 Malignant otitis externa is an invasive, potentially life-threatening infection, especially in immunocompromised patients, and requires prompt diagnosis and treatment with systemic anti-infectives.139
Topical ophthalmic preparations containing neomycin sulfate in fixed combination with polymyxin B sulfate and a corticosteroid (i.e., dexamethasone)119, 120 or neomycin sulfate in fixed combination with polymyxin B sulfate, bacitracin zinc, and a corticosteroid (i.e., hydrocortisone or hydrocortisone acetate)107, 108 are used for the treatment of corticosteroid-responsive ocular conditions when a corticosteroid is indicated and superficial bacterial ocular infection or risk of such infection exists.107, 108, 119, 120
Ophthalmic corticosteroids may be indicated in inflammatory conditions of the palpebral and bulbar conjunctiva, cornea, and anterior segment of the globe where the inherent risk of corticosteroid use in certain infective conjunctivitides is accepted to obtain diminution in edema and inflammation.107, 108, 119, 120 Ophthalmic corticosteroids also may be indicated in the treatment of chronic anterior uveitis and corneal injury from chemical, radiation, or thermal burns or penetration of foreign bodies.107, 108, 119, 120
Although the manufacturers state that use of a fixed-combination ophthalmic preparation containing anti-infectives and a corticosteroid may be indicated in ocular inflammatory conditions when the risk of superficial ocular infection is high or when there is an expectation that potentially dangerous numbers of bacteria will be present in the eye,107, 108, 119, 120 experts state that such preparations should be avoided in patients with bacterial conjunctivitis because of the risk of potentiating the infection.136
Clinicians should consider that use of fixed-combination ophthalmic preparations containing anti-infectives and a corticosteroid may mask the clinical signs of bacterial, fungal, or viral infections; prevent recognition of ineffectiveness of the anti-infectives; and/or increase intraocular pressure.107, 108, 119, 120 (See Precautions Related to Use of Fixed Combinations Containing Corticosteroids under Cautions: Precautions and Contraindications.)
For other uses of neomycin, see 8:12.02 and see 84:04.04.
Neomycin sulfate in fixed combination with polymyxin B sulfate and bacitracin zinc is applied topically to the eye as an ophthalmic ointment.105, 106
Neomycin sulfate in fixed combination with polymyxin B sulfate and gramicidin is applied topically to the eye as an ophthalmic solution.125, 126
Neomycin sulfate also is commercially available in fixed combination with polymyxin B sulfate and a corticosteroid (i.e., dexamethasone) or in fixed combination with polymyxin B sulfate, bacitracin zinc, and a corticosteroid (i.e., hydrocortisone or hydrocortisone acetate) for topical application to the eye as ophthalmic ointments or suspensions.107, 108, 119, 120
Ophthalmic preparations containing neomycin sulfate and other anti-infectives with or without a corticosteroid are for topical ophthalmic use only ;105, 106, 107, 108, 119, 120, 125, 126 these preparations are not for subconjunctival injection and should not be introduced directly into the anterior chamber of the eye.105, 106, 107, 108, 119, 120, 125, 126
Care should be taken to avoid contaminating the container tip with material from the eye, eyelids, fingers, or other source.105, 106, 107, 108, 119, 120, 125, 126
Neomycin sulfate in fixed combination with colistin and hydrocortisone acetate is instilled topically into the ear canal as an otic suspension.109, 110
Neomycin sulfate in fixed combination with polymyxin B sulfate and hydrocortisone is instilled topically into the ear canal as an otic solution or suspension.121, 122, 123, 124
Otic solutions and suspensions containing neomycin sulfate are for topical otic use only ;121, 122, 123, 124 these preparations should not be used in the eyes.109, 110, 122, 123, 124
Prior to topical otic instillation, the ear canal should be thoroughly cleaned and dried.109, 110, 121, 122, 123, 124
The otic preparation may be warmed in the hand, but should not be heated above body temperature since this may affect potency.109, 110
Otic suspensions should be shaken well prior to each use.109, 110, 121, 124
The patient should lie with the affected ear upward.109, 110, 121, 122, 123, 124 The appropriate amount of otic solution or suspension should be instilled into the ear;109, 110, 121, 122, 123, 124 this position should be maintained for 5 minutes to facilitate penetration into the ear canal.109, 110, 121, 122, 123, 124 The procedure should be repeated for the opposite ear if necessary.109, 110, 121, 122, 123, 124
If the ear canal is narrow or edematous and there are concerns that this might impede drug delivery,139 consideration can be given to inserting a cotton wick into the canal and saturating the wick with the otic preparation.109, 110, 121, 122, 123, 124 The manufacturers state that the wick should be kept moist by adding additional otic solution or suspension every 4 hours and should be replaced once every 24 hours.109, 110, 121, 122, 123, 124 Experts state that a wick is unnecessary after ear canal edema subsides, which may occur within 24 hours or a few days after topical otic treatment is initiated.139
Care should be taken to avoid contaminating the tip of the container with material from the ear, fingers, or other source.109, 110, 121, 122, 123, 124
Dosage of neomycin sulfate is expressed in terms of the base.105, 106, 107, 108, 109, 110, 119, 120, 121, 122, 123, 124, 125, 126
Bacterial Ophthalmic Infections
When a fixed-combination ophthalmic ointment containing neomycin sulfate, polymyxin B sulfate, and bacitracin zinc is used for the topical treatment of superficial bacterial infections of the eye in adults, the ophthalmic ointment should be applied to the affected eye(s) every 3 or 4 hours for 7-10 days, depending on the severity of the infection.105, 106
When a fixed-combination ophthalmic solution containing neomycin sulfate, polymyxin B sulfate, and gramicidin is used for the topical treatment of superficial bacterial infections of the eye in adults, 1 or 2 drops of the solution should be instilled in the affected eye(s) every 4 hours for 7-10 days.125, 126 For severe infections, up to 2 drops may be instilled every hour.125, 126
The usual duration of topical anti-infective treatment for bacterial conjunctivitis is 5-10 days;135, 136, 141 some experts state that 5-7 days of such treatment usually is adequate for mild bacterial conjunctivitis.135
When fixed-combination otic suspensions containing neomycin sulfate, colistin, and hydrocortisone acetate are used for the topical treatment of superficial bacterial infections of the external auditory canal (otitis externa) in adults, 5 drops should be instilled into the canal of the affected ear(s) 3 or 4 times daily for up to 10 days.109, 110 When used in children 1 year of age or older, 4 drops of the otic suspension should be instilled into the canal of the affected ear(s) 3 or 4 times daily for up to 10 days.109, 110
When fixed-combination otic solutions or suspensions containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone are used for the topical treatment of superficial bacterial infections of the external auditory canal (otitis externa) in adults, 4 drops should be instilled into the canal of the affected ear(s) 3 or 4 times daily for up to 10 days.121, 122, 123, 124 When used in children 2 years of age or older, 3 drops of the otic solution or suspension should be instilled into the canal of the affected ear(s) 3 or 4 times daily for up to 10 days.121, 122, 123, 124 One manufacturer does not include an age restriction for use of the otic suspension in pediatric patients.121
Topical otic therapy should not be continued for longer than 10 days.109, 110, 121, 122, 123, 124 (See Precautions Related to Otic Administration under Cautions: Precautions and Contraindications.) The optimal duration of topical therapy for the treatment of acute otitis externa has not been determined, but 7-10 days is usually recommended.139 Some experts state that appropriate treatment of acute otitis externa should result in improvement in symptoms (otalgia, pruritus, fullness) within 48-72 hours, although resolution of symptoms may take up to 2 weeks.139
When a fixed-combination ophthalmic ointment containing neomycin sulfate, polymyxin B sulfate, and dexamethasone is used in adults, approximately 1.25 cm (½ inch) of the ointment should be applied in the conjunctival sac of the affected eye(s) up to 3 or 4 times daily.119
When a fixed-combination ophthalmic suspension containing neomycin sulfate, polymyxin B sulfate, and dexamethasone is used in adults and pediatric patients 2 years of age or older with mild disease, 1 or 2 drops of the suspension should be instilled in the conjunctival sac of the affected eye(s) up to 4-6 times daily.120 In severe disease, 1 or 2 drops of the suspension may be instilled every hour initially and dosage tapered by decreasing the frequency of administration as inflammation subsides.120
When a fixed-combination ophthalmic ointment containing neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and hydrocortisone or hydrocortisone acetate is used in adults, the ointment should be applied to the affected eye(s) every 3 or 4 hours, depending on the severity of the condition.107, 108
If there is no improvement after 48 hours of treatment with a fixed-combination preparation containing anti-infectives and a corticosteroid, the patient should be reevaluated.107, 108, 119, 120 (See Precautions Related to Use of Fixed Combinations Containing Corticosteroids under Cautions: Precautions and Contraindications.)
Local irritation and allergic reactions may occur when fixed-combination topical preparations containing neomycin sulfate are used.105, 106, 107, 108, 109, 110, 119, 120, 121, 122, 123, 124, 125, 126 More serious hypersensitivity reactions, including anaphylaxis, have been reported rarely.105, 106, 107, 108, 119, 120, 125, 126
Topical anti-infectives, particularly neomycin sulfate, may cause cutaneous sensitization.105, 106, 107, 108, 109, 110, 119, 120, 121, 122, 123, 124, 125, 126 A precise incidence of hypersensitivity reactions (primarily skin rash) due to topical anti-infectives is not known.105, 106, 107, 108, 109, 110, 125, 126
Local irritation and allergic reactions reported in patients receiving topical ophthalmic preparations containing neomycin sulfate and other anti-infectives include pruritus, edema of the conjunctiva and eyelid, and conjunctival erythema.105, 106, 107, 108, 119, 120, 125, 126 (See Precautions Related to Sensitivity Reactions under Cautions: Precautions and Contraindications.)
There have been reports of bacterial keratitis developing in patients using topical ophthalmic preparations.105, 106, 107, 108, 125, 126 These infections occurred because the patients inadvertently contaminated the multiple-dose container of the ophthalmic preparation; in most reported cases, the patient had concurrent corneal disease or disruption of the ocular epithelial surface.105, 106, 107, 108, 125, 126 (See Precautions Related to Ophthalmic Administration under Cautions: Precautions and Contraindications.)
Precautions and Contraindications
Fixed-combination ophthalmic preparations containing neomycin sulfate and other anti-infectives (i.e., polymyxin B sulfate and bacitracin zinc; polymyxin B and gramicidin) are contraindicated in patients hypersensitive to any ingredient in the formulation.105, 106, 125, 126
Fixed-combination ophthalmic preparations containing neomycin sulfate, other anti-infectives, and a corticosteroid (i.e., dexamethasone, hydrocortisone, or hydrocortisone acetate) are contraindicated in patients hypersensitive to any ingredient in the formulation.107, 108, 119, 120 In addition, these fixed-combination preparations are contraindicated in patients with viral diseases of the cornea and conjunctiva (e.g., epithelial herpes simplex keratitis [dendritic keratitis], vaccinia, varicella) and in patients with mycobacterial infections of the eye or fungal diseases of ocular structures.107, 108, 119, 120
Fixed-combination otic preparations containing neomycin sulfate, colistin, and hydrocortisone acetate are contraindicated in patients hypersensitive to any ingredient in the formulation.109, 110 In addition, these fixed combinations are contraindicated in patients with known or suspected viral infections of the external ear canal (e.g., herpes simplex, varicella zoster).109, 110
Fixed-combination otic preparations containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone are contraindicated in patients hypersensitive to any ingredient in the formulation.121, 122, 123, 124 In addition, these fixed combinations are contraindicated in patients with known or suspected viral infections of the external ear canal (e.g., herpes simplex, vaccinia, varicella zoster).121, 122, 123, 124
Prolonged use of ophthalmic or otic preparations containing neomycin sulfate and other anti-infectives may result in overgrowth of nonsusceptible organisms, including fungi.105, 106, 109, 110, 121, 122, 123, 124, 125, 126 Appropriate therapy should be initiated if superinfection occurs.105, 106, 125, 126 Resistance to neomycin or other anti-infectives in fixed-combination preparations (i.e., bacitracin, colistin, gramicidin, polymyxin B) may develop.105, 106, 125, 126
Serious adverse reactions, including ototoxicity, nephrotoxicity, and neuromuscular blockade, have occurred following topical application of neomycin, especially in patients receiving the drug via peritoneal instillation or irrigation of wounds or surgical sites and in those receiving topical treatment for skin ulcers, granulating wounds, burns, or extensive areas of denuded skin. Instillation of neomycin into the ear of patients undergoing tympanoplasty has caused ototoxicity. The possibility of cumulative toxicity should be considered if neomycin is applied topically in conjunction with systemic aminoglycoside therapy.
Precautions Related to Sensitivity Reactions
During long-term use of topical ophthalmic or otic anti-infectives, patients should be examined periodically for signs of sensitization.105, 106, 107, 108, 109, 110, 121, 122, 123, 124, 125, 126
In patients receiving topical ophthalmic preparations, sensitization may manifest as rash, pruritus, edema of the conjunctiva and eyelid, or conjunctival erythema;105, 106, 107, 108, 125, 126 in patients receiving topical otic preparations, sensitization may manifest as swelling, dry scaling, and pruritus.109, 110, 121, 122, 123, 124 Sensitization to topical ophthalmic or otic preparations may also manifest as failure to heal in some patients.105, 106, 107, 108, 109, 110, 121, 122, 123, 124, 125, 126
Patients should be advised to discontinue ophthalmic or otic preparations if any signs of sensitivity or allergic reactions occur.105, 106, 107, 108, 109, 110, 121, 122, 123, 124, 125, 126 Symptoms usually subside quickly after the preparation is discontinued.105, 106, 107, 108, 109, 110, 121, 122, 123, 124, 125, 126
Patients allergic to one of the fixed-combination preparations should avoid preparations containing any of the component drugs.105, 106, 107, 108, 121, 122, 123, 124, 125, 126 Cross-allergenicity occurs among the aminoglycosides,109, 110, 119, 120 and patients allergic to topical neomycin may also be allergic to other aminoglycosides (e.g., gentamicin, paromomycin, streptomycin).105, 106, 107, 108, 119, 120, 121, 122, 123, 124, 125, 126
Precautions Related to Ophthalmic Administration
Patients should be informed that ophthalmic preparations, if handled improperly, can become contaminated by common bacteria known to cause ocular infections and that serious damage to the eye and subsequent loss of vision may occur if contaminated ophthalmic preparations are used.105, 106, 107, 125, 126 Patients should be advised to avoid allowing the tip of the dispensing container to contact the eye, eyelid, fingers, or any other surface and to not share ophthalmic preparations with others.105, 106, 107, 108, 119, 120, 125, 126
Patients should be advised that their vision may be temporarily blurred after administration of topical ophthalmic preparations.119, 120 Care should be taken in operating machinery or driving a motor vehicle.119, 120
Some manufacturers caution that ophthalmic ointments may delay corneal healing.105, 106, 107, 108
Precautions Related to Otic Administration
Fixed-combination otic preparations containing neomycin sulfate, colistin, and hydrocortisone acetate should be used with caution in patients with a perforated tympanic membrane.109, 110
Fixed-combination otic preparations containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone should not be used in patients with a perforated tympanic membrane.121, 122, 123, 124
Neomycin, especially with prolonged use, can induce permanent sensorineural hearing loss due to cochlear damage, mainly destruction of hair cells in the organ of Corti.109, 110, 121, 122, 123, 124
Patients being treated with otic preparations containing neomycin should be under close clinical observation and such preparations should not be used for longer than 10 consecutive days.109, 110, 121, 122, 123, 124
If otic infections have not improved after 1 week of topical otic treatment, cultures should be obtained to guide further treatment.109, 110, 121, 122, 123, 124
When using fixed-combination otic preparations containing neomycin sulfate to control secondary infection in chronic otitis externa, clinicians should consider that skin in this condition is more liable than normal skin to become sensitized to many substances, including neomycin.109, 110, 121, 122, 123, 124 Sensitization to topical neomycin usually manifests as a low-grade reddening with swelling, dry scaling, and pruritus; it may manifest simply as failure to heal.109, 110, 121, 122, 123, 124 (See Precautions Related to Sensitivity Reactions under Cautions: Precautions and Contraindications.)
Commercially available fixed-combination otic solutions containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone contain potassium metabisulfite,122, 123 a sulfite that can cause allergic-type reactions, including anaphylaxis and life-threatening or less severe asthmatic episodes, in certain susceptible individuals.111, 112, 113, 114, 115, 116, 117, 118, 122, 123 The overall prevalence of sulfite sensitivity in the general population is unknown but probably low; such sensitivity appears to occur more frequently in asthmatic than in nonasthmatic individuals.117, 122, 123
Precautions Related to Use of Fixed Combinations Containing Corticosteroids
When ophthalmic or otic preparations containing neomycin sulfate in fixed combination with other anti-infectives and a corticosteroid (i.e., dexamethasone, hydrocortisone, or hydrocortisone acetate) are used, the usual cautions, precautions, and contraindications associated with the corticosteroid also must be considered.107, 108, 119, 120, 121, 122, 123, 124
Initial prescriptions for fixed-combination ophthalmic preparations containing a corticosteroid or renewal prescriptions (beyond 8 g of ophthalmic ointment or beyond 20 mL of ophthalmic suspension) should be made only after examining the patient with slit lamp microscopy and, when appropriate, fluorescein staining.107, 108, 119, 120
Patients should be advised to discontinue the fixed-combination ophthalmic preparation and contact a clinician if inflammation or pain persists for more than 48 hours or becomes aggravated.108, 119, 120
Prolonged use of fixed-combination ophthalmic preparations containing a corticosteroid may result in glaucoma, with damage to the optic nerve, defects in visual acuity and fields of vision, and posterior subcapsular cataract formation.107, 108, 119, 120 If an ophthalmic preparation containing a corticosteroid is used for 10 days or longer, intraocular pressure should be routinely monitored, even though this may be difficult in children and uncooperative patients.107, 108, 119, 120 Such preparations should be used with caution in patients with glaucoma and intraocular pressure should be checked frequently in such patients.107, 108, 119, 120
Use of fixed-combination ophthalmic preparations containing a corticosteroid after cataract surgery may delay healing and increase the incidence of bleb formation.107, 108, 119, 120
Various ocular diseases and long-term use of topical ophthalmic corticosteroids have caused corneal and scleral thinning.108, 120 Use of topical ophthalmic corticosteroids in patients with thin corneal and scleral tissue may result in perforation.107, 108, 119, 120
Prolonged use of fixed-combination ophthalmic preparations containing a corticosteroid may suppress host responses and increase the risk of secondary ocular infections.107, 108, 119, 120 Use of such preparations in patients with acute purulent or parasitic infections of the eye may mask infection or enhance existing infection.107, 108, 119, 120
Use of ophthalmic preparations containing a corticosteroid may prolong the course and exacerbate severity of many viral infections of the eye (including herpes simplex).107, 108, 119, 120 Such preparations should be used with great caution in patients with herpes simplex107, 108, 119, 120 and frequent slit lamp microscopy is recommended.108, 119, 120
The possibility of fungal infections of the cornea should be considered after prolonged use of ophthalmic preparations containing a corticosteroid,107, 108, 119, 120 especially in patients with persistent corneal ulceration.119, 120 Fungal cultures should be taken when appropriate.107, 108, 119, 120
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and bacitracin zinc (ophthalmic): Safety and efficacy have not been established in pediatric patients.105, 106
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and gramicidin (ophthalmic): Safety and efficacy have not been established in pediatric patients.125, 126
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and dexamethasone (ophthalmic): Safety and efficacy of the suspension have not been established in children younger than 2 years of a 120 safety and efficacy of the ointment have not been established in pediatric patients.119
Fixed combinations of neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and either hydrocortisone or hydrocortisone acetate (ophthalmic): Safety and efficacy have not been established in pediatric patients.107, 108
Fixed combinations of neomycin sulfate, colistin, and hydrocortisone acetate (otic): Safety and efficacy have not been established in children younger than 1 year of age.109, 110 Safety and efficacy in those 1 year of age or older have been demonstrated in a controlled clinical trial.109, 110
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and hydrocortisone (otic): Most manufacturers state that safety and efficacy have not been established for the treatment of otitis external in children younger than 2 years of age because of insufficient data in this age group.122, 123, 124 One manufacturer states that safety and efficacy have been established in pediatric patients and does not specify an age range.121
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and gramicidin (ophthalmic): Clinical studies did not include sufficient numbers of patients 65 years of age or older to determine whether they respond differently than younger adults.125 Other reported clinical experience has not identified differences in responses between geriatric and younger patients.125
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and dexamethasone (ophthalmic): No overall differences in safety or efficacy have been observed between geriatric and younger patients.119, 120
Fixed combinations of neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and hydrocortisone acetate (ophthalmic): No overall differences in safety or efficacy have been observed between geriatric and younger adults.108
Fixed combinations of neomycin sulfate, colistin, and hydrocortisone acetate (otic): No overall differences in safety or efficacy have been observed between geriatric and younger adults.109, 110
Fixed combinations of neomycin sulfate, polymyxin B sulfate, and hydrocortisone (otic): Clinical studies did not include sufficient numbers of patients 65 years of age or older to determine whether they respond differently than younger adults.121, 122, 123, 124 Other reported clinical experience has not identified differences in responses between geriatric and younger patients.121, 122, 123, 124
Animal reproduction studies have not been conducted with neomycin sulfate.105, 106, 125, 126 It is not known whether ophthalmic or otic preparations containing neomycin sulfate can cause fetal harm when administered to a pregnant woman.105, 106, 109, 110, 125, 126
Fixed-combination ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and either bacitracin zinc or gramicidin should be used during pregnancy only if clearly needed.105, 106, 125, 126
Fixed-combination ophthalmic preparations containing neomycin sulfate, other anti-infectives (i.e., polymyxin B sulfate, bacitracin zinc), and a corticosteroid (i.e., dexamethasone, hydrocortisone, hydrocortisone acetate) should be used during pregnancy only if potential benefits justify potential risks to the fetus.107, 108, 119, 120
Fixed-combination otic preparations containing neomycin sulfate, colistin, and hydrocortisone acetate should be used during pregnancy only if potential benefits justify potential risks to the fetus.109, 110 Although aminoglycosides can cause congenital deafness in humans if administered during pregnancy, the manufacturers state that clinically important systemic concentrations of neomycin are not anticipated when otic preparations containing neomycin are used as directed.109, 110
Fixed-combination otic preparations containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone should be used during pregnancy only if potential benefits justify potential risks to the fetus.121, 122, 123, 124
It is not known whether neomycin is distributed into milk.144
Fixed-combination ophthalmic preparations containing neomycin sulfate and other anti-infectives (i.e., bacitracin zinc, gramicidin, polymyxin B sulfate) should be used with caution in nursing women.105, 106, 125, 126
Fixed-combination ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, and dexamethasone should be used with caution in nursing women.119, 120
The manufacturers of fixed-combination ophthalmic preparations containing neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and hydrocortisone or hydrocortisone acetate state that a decision should be made whether to discontinue nursing or the ophthalmic preparation, taking into account the importance of the drug to the woman.107, 108
Fixed-combination otic preparations containing neomycin sulfate, colistin, and hydrocortisone acetate and fixed-combination otic preparations containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone should be used with caution in nursing women.109, 110, 121, 122, 123, 124
Neomycin usually is bactericidal in action. Although the exact mechanism of action has not been fully elucidated, the drug appears to inhibit protein synthesis in susceptible bacteria by binding with ribosomal RNA and causing misreading of the bacterial genetic code.
In general, neomycin is active against many aerobic gram-negative bacteria and some aerobic gram-positive bacteria. Neomycin is inactive against fungi, viruses, and most anaerobic bacteria.
In vitro, neomycin concentrations of 1-12.5 mcg/mL inhibit most susceptible Enterobacter , Escherichia coli , Haemophilus influenzae , Klebsiella , Moraxella lacunata , Neisseria , indole-positive and indole-negative Proteus , Staphylococcus aureus and S. epidermidis . Streptococci (including Streptococcus pneumoniae ) generally are resistant to the drug.
Neomycin sulfate in fixed combination with polymyxin B sulfate is considered active against S. aureus , E. coli , H. influenzae , Enterobacter , Klebsiella , Neisseria , and Pseudomonas aeruginosa ,119, 120, 121, 122, 123, 124 but does not provide adequate coverage against streptococci (including S. pneumoniae ) or Serratia marcescens .119, 120, 121, 122, 123, 124
Neomycin sulfate in fixed combination with polymyxin B sulfate and bacitracin zinc is considered active against S. aureus , streptococci (including S. pneumoniae ), E. coli , H. influenzae , Enterobacter , Klebsiella , Neisseria , and Ps. aeruginosa ,105, 106, 107, 108 but does not provide adequate coverage against S. marcescens .105, 106, 107, 108
Neomycin sulfate in fixed combination with polymyxin B sulfate and gramicidin is considered active against S. pneumoniae , E. coli , H. influenzae , Enterobacter , Klebsiella , Neisseria , and Ps. aeruginosa , but does not provide adequate coverage against S. marcescens .125, 126
Neomycin sulfate in fixed combination with colistin is active in vitro and in superficial infections of the external auditory canal caused by S. aureus , E. aerogenes , E. coli , K. pneumoniae , and Ps. aeruginosa .109, 110
Natural and acquired resistance to neomycin has been demonstrated in gram-negative and gram-positive bacteria. Resistance may be caused by decreased permeability of the bacterial cell wall, alterations in the ribosomal binding site, or the presence of a plasmid-mediated resistance factor which is acquired by conjugation. Plasmid-mediated resistance enables the resistant bacteria to enzymatically modify the drug by acetylation, phosphorylation, or adenylylation and can be transferred between organisms of the same or different species. Resistance to other aminoglycosides and several other anti-infectives (e.g., chloramphenicol, sulfonamides, tetracycline) may be transferred on the same plasmid.
Bacteria resistant to neomycin may emerge in patients receiving topical ophthalmic preparations containing the drug.105, 106, 125, 126
There is partial cross-resistance between neomycin and other aminoglycosides; cross-resistance occurs frequently between kanamycin, neomycin, and paromomycin.
Studies in rabbits suggest that neomycin is absorbed into the aqueous humor following topical instillation onto the eye of a neomycin sulfate solution containing 40 mg/mL; absorption of the drug is greatest when the cornea is abraded. In dogs, neomycin is absorbed through the ear, especially when applied to the ear canals of dogs with perforated tympanic membranes.
Neomycin is an aminoglycoside antibiotic obtained from cultures of Streptomyces fradiae . Neomycin is a mixture of neomycin A (neamine), neomycin B, and neomycin C. Commercially available neomycin is comprised almost entirely of the sulfate salt of neomycin B and occurs as a white to slightly yellow, hygroscopic powder or cryodesiccated solid and is freely soluble in water and very slightly soluble in alcohol.
Neomycin sulfate is commercially available for topical ophthalmic use only in fixed combination with other anti-infectives.105, 106, 125, 126 This includes fixed-combination ophthalmic ointments containing neomycin sulfate, polymyxin B sulfate, and bacitracin zinc105, 106 and fixed-combination ophthalmic solutions containing neomycin sulfate, polymyxin B sulfate, and gramicidin.125, 126 The ophthalmic solutions containing neomycin, polymyxin B, and gramicidin contain thimerosal as a preservative.125, 126
Neomycin sulfate also is commercially available for topical ophthalmic use as fixed-combination ophthalmic ointments or suspensions containing other anti-infectives and a corticosteroid.107, 108, 119, 120 This includes fixed-combination ointments or suspensions containing neomycin sulfate, polymyxin B sulfate, and dexamethasone119, 120 and fixed-combination ointments containing neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and either hydrocortisone or hydrocortisone acetate.107, 108 The ophthalmic ointments containing neomycin, polymyxin B, and dexamethasone contain methylparaben and propylparaben as preservatives;119 the ophthalmic suspensions contain benzalkonium chloride as a preservative.120
For topical otic use, neomycin sulfate is commercially available in fixed-combination otic suspensions containing neomycin sulfate, colistin, and hydrocortisone acetate.109, 110 These suspensions also contain thonzonium bromide, a surface-active agent that facilitates dispersion and penetration of cellular debris and exudate, and contain thimerosal as a preservative.109, 110
For topical otic use, neomycin sulfate also is commercially available in fixed-combination otic solutions or suspensions containing neomycin sulfate, polymyxin B sulfate, and a corticosteroid (i.e., hydrocortisone).121, 122, 123, 124 The otic solutions containing neomycin, polymyxin B, and hydrocortisone contain potassium metabisulfite as a preservative (see Precautions Related to Otic Administration under Cautions: Precautions and Contraindications);122, 123 the suspensions contain thimerosal as a preservative.121, 124
Fixed-combination ophthalmic ointments containing neomycin sulfate, polymyxin B sulfate, and bacitracin zinc should be stored at 15-25°C.105, 106
Fixed-combination ophthalmic solutions containing neomycin sulfate, polymyxin B sulfate, and gramicidin should be stored at 15-25°C125, 126 and protected from light.125
Fixed-combination ophthalmic ointments containing neomycin sulfate, polymyxin B sulfate, and dexamethasone should be stored at 2-25°C.119 Fixed-combination ophthalmic suspensions containing these drugs should be stored upright at 8-25°C.120
Fixed-combination ophthalmic ointments containing neomycin sulfate, polymyxin B sulfate, bacitracin zinc, and either hydrocortisone or hydrocortisone acetate should be stored at 15-25°C.107, 108
Fixed-combination otic suspensions containing neomycin sulfate, colistin, and hydrocortisone acetate should be stored at 20-25°C.109, 110
Fixed-combination otic solutions or suspensions containing neomycin sulfate, polymyxin B sulfate, and hydrocortisone should be stored at 15-25°C.121, 122, 123, 124
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.
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.
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Otic | Suspension | Colistin Sulfate 3 mg (of colistin) per mL, Neomycin Sulfate 3.3 mg (of neomycin), and Hydrocortisone Acetate 1% | Coly-Mycin® S Otic with Neomycin and Hydrocortisone | |
Cortisporin®-TC Otic Suspension |
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Ointment | Neomycin Sulfate 3.5 mg (of neomycin) per g, Polymyxin B Sulfate 10,000 units (of polymyxin B) per g, and Bacitracin Zinc 400 units (of bacitracin) per g* | Neomycin and Polymyxin B Sulfates and Bacitracin Zinc Ophthalmic Ointment | |
Neosporin® Ophthalmic Ointment |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Ointment | Neomycin Sulfate 3.5 mg (of neomycin) per g, Polymyxin B Sulfate 10,000 units (of polymyxin B) per g, Bacitracin Zinc 400 units (of bacitracin) per g, and Hydrocortisone 1%* | Neomycin and Polymyxin B Sulfates, Bacitracin Zinc, and Hydrocortisone Ophthalmic Ointment |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Ointment | Neomycin Sulfate 3.5 mg (of neomycin) per g, Polymyxin B Sulfate 10,000 units (of polymyxin B) per g, Bacitracin Zinc 400 units (of bacitracin) per g, and Hydrocortisone Acetate 1%* | Neomycin and Polymyxin B Sulfates, Bacitracin Zinc, and Hydrocortisone Acetate Ophthalmic Ointment |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Ointment | Neomycin Sulfate 3.5 mg (of neomycin) per g, Polymyxin B Sulfate 10,000 units (of polymyxin B) per g, and Dexamethasone 0.1%* | ||
Neomycin and Polymyxin B Sulfates and Dexamethasone Ophthalmic Ointment | ||||
Suspension | Neomycin Sulfate 3.5 mg (of neomycin) per mL, Polymyxin B Sulfate 10,000 units (of polymyxin B) per mL, and Dexamethasone 0.1%* | Maxitrol® | Alcon | |
Neomycin and Polymyxin B Sulfates and Dexamethasone Ophthalmic Suspension |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Solution | Neomycin Sulfate 1.75 mg (of neomycin) per mL, Polymyxin B Sulfate 10,000 units (of polymyxin B) per mL, and Gramicidin 0.025 mg per mL* | Neomycin and Polymyxin B Sulfates and Gramicidin Ophthalmic Solution | |
Neosporin® Ophthalmic Solution |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Suspension | Neomycin Sulfate 3.5 mg (of neomycin) per mL, Polymyxin B Sulfate 10,000 units (of polymyxin B) per mL, and Hydrocortisone 1%* | Neomycin and Polymyxin B Sulfates and Hydrocortisone Ophthalmic Solution | |
Otic | Solution | Neomycin Sulfate 3.5 mg (of neomycin) per mL, Polymyxin B Sulfate 10,000 units (of polymyxin B) per mL, and Hydrocortisone 1%* | Cortisporin® Otic Solution | Pfizer |
Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Solution | ||||
Suspension | Neomycin Sulfate 3.5 mg (of neomycin) per mL, Polymyxin B Sulfate 10,000 units (of polymyxin B) per mL, and Hydrocortisone 1%* | Casporyn® HC | ||
Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Suspension |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
AHFS® Drug Information. © Copyright, 1959-2025, Selected Revisions July 10, 2024. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
Only references cited for selected revisions after 1984 are available electronically.
105. MWI. Neomycin and polymyxin B sulfates and bacitracin zinc ophthalmic ointment USP prescribing information. Boise, ID; 2016 Oct.
106. Burroughs Wellcome. Neosporin® (neomycin and polymyxin B sulfates and bacitracin zinc) ophthalmic ointment USP prescribing information. Research Triangle Park, NC; undated.
107. Bausch & Lomb. Neomycin and polymyxin B sulfates, bacitracin zinc and hydrocortisone ophthalmic ointment USP prescribing information. Bridgewater, NJ; 2016 Nov.
108. E. Fougera & Co. Neomycin and polymyxin B sulfates and bacitracin zinc with hydrocortisone acetate ophthalmic ointment prescribing information. Melville, NY. 2004 Aug.
109. Endo Pharmaceuticals. Coly-Mycin® S (colistin sulfate, neomycin sulfate, thonzonium bromide and hydrocortisone acetate otic suspension prescribing information. Malvern, PA; 2016 Jan.
110. Par Pharmaceuticals. Cortisporin®-TC (colistin sulfate, neomycin sulfate, thonzonium bromide and hydrocortisone acetate otic suspension prescribing information. Chestnut Ridge, NY; 2015 Apr.
111. Food and Drug Administration. Sulfites in foods and drugs. FDA Drug Bull . 1983; 13:12. [PubMed 6604672]
112. Sogn D. The ubiquitous sulfites. JAMA . 1984; 251:2986 7. Editorial. [PubMed 6716628]
113. Koepke JW, Christopher KL, Chai H et al. Dose dependent bronchospasm from sulfites in isoetharine. JAMA . 1984; 251:2982 3. [PubMed 6716626]
114. Twarog FJ, Leung DYM. Anaphylaxis to a component of isoetharine (sodium bisulfite). JAMA . 1982; 248:2030 1. [PubMed 7120631]
115. Baker GJ, Collett P, Allen DH. Bronchospasm induced by metabisulphite containing foods and drugs. Med J Aust . 1981; 2:614 7. [PubMed 7334982]
116. Koepke JW, Selner JC, Dunhill AL. Presence of sulfur dioxide in commonly used bronchodilator solutions. J Allergy Clin Immunol . 1983; 72:504 8. [PubMed 6630799]
117. Food and Drug Administration. Sulfiting agents; labeling in drugs for human use: warning statement. [Docket No. 84N 0113] Fed Regist . 1985; 50:47558 63.
118. Food and Drug Administration Center for Food Safety and Applied Nutrition. The reexamination of the GRAS status of sulfiting agents, January 1985. (Doc. No. 223-83-2020.) Bethesda, MD: FASEB Life Sciences Research Office.
119. Alcon Laboratories, Inc. Maxitrol® (neomycin and polymyxin B sulfates and dexamethasone) ophthalmic ointment prescribing information. Fort Worth, TX; 2017 Dec.
120. Alcon Laboratories, Inc. Maxitrol® (neomycin and polymyxin B sulfates and dexamethasone) ophthalmic suspension prescribing information. Fort Worth, TX; 2017 Dec.
121. Casper Pharma. Casporyn® HC (neomycin and polymyxin B sulfates and hydrocortisone) otic suspension, USP. East Brunswick, NJ; 2017 Dec.
122. Bausch & Lomb. Neomycin and polymyxin B sulfates and hydrocortisone otic solution, USP prescribing information. Bridgewater, NJ; 2016 Aug.
123. Pfizer Laboratories. Cortisporin® (neomycin and polymyxin B sulfates and hydrocortisone) otic solution, USP prescribing information. New York, NY; 2016 Aug.
124. Bausch & Lomb. Neomycin and polymyxin B sulfates and hydrocortisone otic suspension, USP prescribing information. Bridgewater, NJ; 2016 Aug.
125. Pfizer. Neosporin® (neomycin and polymyxin B sulfates and gramicidin) ophthalmic solution, USP prescribing information. Bristol, TN; 2016 Jul.
126. Bausch & Lomb. Neomycin and polymyxin B sulfates and gramicidin ophthalmic solution, USP prescribing information. Bridgewater, NJ; 2016 Jun.
135. American Academy of Ophthalmology. Preferred practice pattern (PPP) guidelines: conjunctivitis PPP - 2013. From American Academy of Ophthalmology website. Accessed 20 Dec 2017. [Web]
136. Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. JAMA . 2013; 310:1721-9. [PubMed 24150468]
137. Sheikh A, Hurwitz B, van Schayck CP et al. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database Syst Rev . 2012; :CD001211. [PubMed 22972049]
138. American Academy of Ophthalmology. Preferred Practice Pattern (PPP) guidelines: bacterial keratitis - 2013. From the American Academy of Ophthalmology website. Accessed 5 Dec 2016. [Web]
139. Rosenfeld RM, Schwartz SR, Cannon CR et al. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg . 2014; 150(1 Suppl):S1-S24. [PubMed 24491310]
141. Barnes SD, Kumar NM, Pavin-Langston D et al. Microbial Conjunctivitis. In: Bennett JE, Dolin R, and Blaser MJ, eds. Mandell, Douglas, and Bennett's principles and practices of infectious diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:1392-1401.
143. Kaushik V, Malik T, Saeed SR. Interventions for acute otitis externa. Cochrane Database Syst Rev . 2010; :CD004740. [PubMed 20091565]
144. Teva Pharmaceuticals USA. Neomycin sulfate tablets USP prescribing information. North Wales, PA; 2015 Aug.