Dexamethasone with hypromellose, neomycin and polymyxin B sulfate

How it works

Dexamethasone suppresses ocular inflammation by inhibiting inflammatory mediators; neomycin (an aminoglycoside) and polymyxin B provide broad Gram-negative and some Gram-positive antibacterial cover, while hypromellose lubricates and prolongs contact time.

Prescribing in practice

• Topical corticosteroids must not be used in undiagnosed red eye or suspected herpes simplex (dendritic) keratitis, where they can cause rapid corneal melting and sight loss, so a herpetic cause must be excluded.
• Prolonged use risks steroid-induced glaucoma, cataract and masking or worsening of infection, so courses should be short and ophthalmologist-supervised.
• Neomycin is a frequent cause of contact hypersensitivity; discontinue if local allergic reaction develops.

Monitoring

With more than short-term use, monitor intraocular pressure and review the cornea and clinical response, stopping if infection worsens or hypersensitivity appears.

Counselling the patient

• Use only for the prescribed short course and do not keep using it for future eye problems.
• Stop and seek advice if the eye becomes more painful, red or swollen, which may indicate an allergy or worsening infection.
• Remove contact lenses during treatment unless your clinician advises otherwise.

Evidence & guidelines

Combined steroid-antibiotic eye preparations are well established for inflammatory eye conditions with a bacterial component, with safe use depending on excluding viral keratitis and limiting duration.