What is the appropriate dosing regimen for Maxitrol (dexamethasone‑neomycin‑polymyxin B) ophthalmic suspension in adults and children, including infants, and what are its contraindications?

Maxitrol Dosing

For bacterial blepharitis and conjunctivitis with inflammatory components, administer Maxitrol (dexamethasone 0.1%/neomycin/polymyxin B) ophthalmic suspension 4 times daily, with treatment duration guided by clinical response, typically ranging from several days to weeks. 1

Standard Dosing Regimen

• Instill 1-2 drops into the affected eye(s) 4 times daily for bacterial blepharitis and inflammatory ocular conditions where bacterial infection risk exists 1
• Treatment duration should be individualized based on clinical response, typically ranging from a few days for acute conjunctivitis to several weeks for chronic blepharitis 1
• For chronic blepharitis, symptoms often recur when treatment is discontinued, necessitating intermittent reinstatement based on severity 1

Pediatric Considerations

• Maxitrol can be used in children, though specific pediatric dosing is not distinctly different from adults in the available evidence 2, 3
• For bacterial conjunctivitis in children, treatment typically consists of 4 times daily administration for 5-7 days 2
• Children can generally return to school once treatment has been initiated for 24 hours and symptoms begin to improve 2

Clinical Efficacy Evidence

• Maxitrol demonstrates superior bacterial eradication (50%) compared to dexamethasone alone (17%) in chronic blepharitis and conjunctivitis 3
• The combination produces a 90% reduction in bacterial counts versus 34% with steroid alone 3
• Maxitrol significantly reduces conjunctival discharge more effectively than steroid monotherapy while providing equal relief of other ocular signs and symptoms 3

Critical Safety Considerations and Contraindications

Maxitrol is contraindicated as monotherapy for bacterial keratitis and should be reserved for inflammatory conditions where infection risk exists but corneal ulceration is not present 1

Major Contraindications:

• Viral diseases of the cornea and conjunctiva including epithelial herpes simplex keratitis, vaccinia, and varicella 1
• Mycobacterial infection of the eye 1
• Fungal diseases of ocular structures 1
• Active bacterial keratitis or corneal ulceration (requires referral to ophthalmology) 1, 2

High-Risk Situations Requiring Caution:

• Avoid preserved formulations when epithelial defects are present, as preservatives worsen epithelial damage 1
• Do not use in patients with undiagnosed Sjögren's syndrome or severe dry eye, as case reports document corneal perforation following routine use post-cataract surgery in these patients 4
• Avoid combination with eye patching, especially in contact lens wearers, due to increased bacterial keratitis risk 1

Duration Limitations and Steroid-Sparing Strategies

• For treatment exceeding 8 weeks, consider switching to loteprednol etabonate 0.5%/tobramycin 0.3% (Zylet) as a safer alternative due to lower risk of intraocular pressure elevation and cataract progression 1
• Monitor intraocular pressure regularly with prolonged corticosteroid use, as dexamethasone carries significant risk of steroid-induced glaucoma 5
• Consider early introduction of corticosteroid-sparing agents (e.g., ciclosporin drops) for moderate-to-severe inflammatory conditions requiring extended therapy 5

Antibiotic Resistance Considerations

• Rotate antibiotic formulations intermittently using different mechanisms of action to prevent resistant organism development 1
• Avoid chronic prophylactic use without clear indication, as this promotes resistant organism growth, particularly methicillin-resistant Staphylococcus aureus 1, 2
• Be aware that neomycin (a component of Maxitrol) carries well-known toxic problems with long-term use, including contact dermatitis and hypersensitivity reactions 3

When to Refer to Ophthalmology

Immediate ophthalmology referral is required for: 2

• Visual loss or progressive decrease in visual acuity
• Severe pain or moderate-to-severe pain
• Corneal involvement, ulceration, or stromal thinning
• Lack of response to therapy after 3-4 days
• Severe purulent discharge
• Contact lens wearers with bacterial conjunctivitis (higher complication risk)

Common Pitfalls to Avoid

• Never use Maxitrol as sole therapy for bacterial keratitis—this requires fortified antibiotics and ophthalmology management 1
• Do not prescribe for patients with active viral keratitis, as corticosteroids can worsen herpetic disease 1
• Avoid in patients with undiagnosed dry eye syndromes or autoimmune conditions affecting tear production, as this increases perforation risk 4
• Do not continue beyond 2 weeks without reassessment and consideration of alternative diagnoses or resistant organisms 2