Maxitrol®

neomycin 0.35%, polymyxin B, dexamethasone 0.1% · ophthalmic suspension

Antibiotic/Steroid

Approved uses

Steroid-responsive ocular inflammation where bacterial infection or a risk of infection exists

1 to 2 drops in the conjunctival sac; hourly in severe disease with taper, up to 4 to 6 times daily in mild disease; not more than 20 mL before re-examination

Controls post-cataract cells and flare as well as tobramycin-dexamethasone, with no 10 mmHg IOP rise.

Contraindications

Most viral diseases of the cornea and conjunctiva, including epithelial herpes simplex keratitis (dendritic keratitis), vaccinia, and varicella.
Mycobacterial infection of the eye.
Fungal disease of ocular structures.
Known or suspected hypersensitivity to any ingredient of this preparation or to other corticosteroids.

Available Forms

Neomycin 3.5 mg/mL, polymyxin B sulfate 10,000 units/mL, dexamethasone 0.1% suspension, 5 mL in an 8 mL bottle.

Mechanism of Action

Corticosteroid plus two antibacterials: dexamethasone suppresses the inflammatory response and probably delays or slows healing, neomycin binds the bacterial 30S ribosomal subunit to block protein synthesis, and polymyxin B permeabilizes the gram-negative outer membrane. The pairing supplies antibacterial cover where corticosteroid inhibition of host defense against infection is clinically significant.

Warnings & Precautions

Neomycin sensitization: Cutaneous sensitization may occur, ranging from local effects to erythema, itching, urticaria, skin rash, anaphylaxis, anaphylactoid reactions, or bullous reactions; discontinue if hypersensitivity develops.
Aminoglycoside cross-sensitivity: Sensitization to the topical aminoglycoside may extend to other topical or systemic aminoglycosides.
Periocular contact allergy: In a German patch test series of periorbital dermatitis, allergic contact dermatitis was the leading cause (44.3% and 31.6% across two cohorts) and neomycin sulfate ranked among the five most relevant allergens at 8%.
Prolonged corticosteroid use: Glaucoma with optic nerve damage, defects in visual acuity and fields of vision, and posterior subcapsular cataract formation.
Host response suppression: Prolonged use increases the hazard of secondary ocular infection, and prolonged topical antibacterial use may allow overgrowth of non-susceptible organisms including fungi; suspect fungal invasion in any persistent corneal ulceration where a corticosteroid has been used, and culture when appropriate.
Infection masking: Acute purulent or parasitic ocular infection may be masked or its activity enhanced by corticosteroid.
Herpes simplex exacerbation: Ocular steroids may prolong the course and worsen many viral eye infections; treating a patient with a history of herpes simplex requires great caution and frequent slit lamp microscopy.
Corneal and scleral thinning: Ocular disease and long-term topical corticosteroids thin these tissues, and use over thin cornea or sclera may lead to perforation.
IOP monitoring at 10 days: Routine monitoring is required with use of 10 days or longer, including in children and uncooperative patients; use with caution in glaucoma and check IOP frequently.
Post-cataract surgery healing: Steroid use after cataract surgery may delay healing and increase the incidence of bleb formation.
Route restriction: Not for injection; it should never be injected subconjunctivally or introduced into the anterior chamber.
Coverage gap: No adequate coverage against Serratia marcescens or streptococci, including Streptococcus pneumoniae.
Two-day reassessment: Re-evaluate if signs and symptoms fail to improve after two days.
Transient blurred vision: Vision may be temporarily blurred after dosing, which matters for driving and machinery.

Common Side Effects

Hypersensitivity: Allergic sensitization is the reaction reported most often from the anti-infective components; exact incidence figures are not available.
Ocular, corticosteroid: IOP elevation with possible glaucoma and infrequent optic nerve damage, posterior subcapsular cataract formation, and delayed wound healing; globe perforation has been reported with corticosteroid-containing preparations.
Ocular, other: Keratitis, conjunctivitis, corneal ulcer, and conjunctival hyperemia occasionally reported with steroid use, and ulcerative keratitis in postmarketing use.
Systemic: Headache and Stevens-Johnson syndrome in postmarketing use; Cushing's syndrome and adrenal suppression after dosing in excess of label instructions in predisposed patients, including children and patients on CYP3A4 inhibitors.

Pregnancy & Lactation

Pregnancy: Dexamethasone is teratogenic in mice and rabbits after topical ocular application at multiples of the therapeutic dose, with fetal resorption and cleft palate in mice and head, ear, limb, and palate defects in rabbits; no adequate human studies, prolonged or repeated corticoid use in pregnancy is associated with intrauterine growth retardation, and infants exposed to substantial maternal corticosteroid doses should be watched for hypoadrenalism.

Lactation: Systemically administered corticosteroids appear in human milk and could suppress growth or interfere with endogenous corticosteroid production; whether topical ocular dosing yields detectable milk levels is unknown, so use with caution.

Pediatric Use

Safety and effectiveness below 2 years of age not established.