Indications
Eye: Inflammatory conditions (eg. uveitis, marginal keratitis, allergic conjunctivitis, blepharitis and episcleritis) where development of bacterial infection is likely.
Ear: Otitis externa and other inflammatory conditions where bacterial infection is present or suspected.
Nose: Inflammatory conditions where infection is present or suspected.
Pharmacology
Betamethasone is a corticosteroid which is effective in inflammatory dermatoses. It is also effective in less responsive conditions such as psoriasis. Betamethasone has a 16β-methyl group that enhances the anti-inflammatory action of the molecule and reduces the sodium and water retaining properties of the fluorine atom bound at carbon 9.
Neomycin sulfate is bactericidal against many bacteria which are commonly associated with skin infections. Neomycin is a broad spectrum antibiotic which actively transported across the bacterial cell membrane, binds to a specific receptor protein on the 30s subunit of bacterial ribosomes, and interferes with an initiation complex between mRNA (messenger RNA) and the 30s subunit, inhibiting protein synthesis. DNA may be misread, thus producing nonfunctional proteins; polyribosomes are split apart and are unable to synthesize protein.
Dosage And Administration
Drops:
- Eye: 1 drop instilled into the eye every one or two hours until control is achieved, when the frequency may be reduced.
- Ear: 2 or 3 drops instilled into the ear, every two or three hours until control is achieved, when the frequency can be reduced.
- Nose: 2 or 3 drops instilled into each nostril two or three times daily.
Eye Ointment: It should be applied thinly and evenly to the conjunctival sac at night (If eye drops used during day) or 3-4 times daily (if ointment used alone).
Contraindications
Viral, fungal, tuberculous or purulent conditions. Use in the eye is contra-indicated if glaucoma is present or where herpetic keratitis (e.g. dendritic ulcer) is considered a possibility. Inadvertent use of topical steroids in the latter condition can lead to extension of the ulcer and marked visual deterioration. Preparations containing neomycin should not be used for treating otitis externa when the ear drum is perforated, because of the risk of ototoxicity.
Side Effects
Acute sensitization to neomycin is a rare event but can occur after topical application to the eye. Eye drops containing corticosteroids cause a serious rise in intra-ocular pressure in a small percentage of the population, including most of those with a family history of glaucoma. A milder rise may be experienced by a larger proportion of subjects if treatment is continued for longer than a few weeks. Thinning of the cornea leading to perforation has occurred with use of topical corticosteroids. Cataract is reported to have occurred after unduly prolonged treatment of eye conditions with topical corticosteroids.
Pregnancy And Lactation
Pregnancy Category-Not Classified. FDA has not yet classified the drug into a specified pregnancy category. Topical administration of corticosteroid to pregnant animals can cause abnormalities of fetal development. The relevance of this finding to human beings has not been established; however, topical steroids should not be used extensively in pregnancy, i.e. in large amounts or for prolonged periods.
Precautions And Warnings
Steroids should not be administered to "red eyes" until a definitive diagnosis has been made. Ophthalmological treatment with steroid preparations should not be repeated or prolonged without regular review to exclude raised intra-ocular pressure or unsuspected infections. The unnecessary topical use of neomycin containing products should be avoided in order to minimize the occurrence of neomycin-resistant organisms (and organism cross-resistant to other aminoglycosides).
Therapeutic Class
Ophthalmic steroid - antibiotic combined preparations
Storage Conditions
Store below 25° C