Gramacidin + Neomycin + Polymixin B (Eye prep)
Indications
Gramacidin + Neomycin + Polymixin B (Eye prep) is used for:
Conjunctivitis, Keratitis, Blepharitis, Superficial bacterial infections, Corneal ulcer, Keratoconjunctivitis
Adult Dose
Adult & child: 1-2 drops into the affected eye every 4-6 times daily for 7 to 10 days. In severe infections, dosage may be increased to as much as two drops every hour.
Child Dose
Renal Dose
Administration
Contra Indications
This product is contraindicated in those persons who have shown hypersensitivity to any of its components.
Precautions
As with other antibiotic preparations, prolonged use of this product may result in overgrowth of nonsusceptible organisms including fungi. If superinfection occurs, appropriate measures should be initiated.
Bacterial resistance to this product may also develop. If purulent discharge, inflammation or pain becomes aggravated, the patient should discontinue use of the medication and consult a physician.
There have been reports of bacterial keratitis associated with the use of topical ophthalmic products in multiple-dose containers which have been inadvertently contaminated by patients, most of whom had a concurrent corneal disease or a disruption of the ocular epithelial surface .
Allergic cross-reactions may occur which could prevent the use of any or all of the following antibiotics for the treatment of future infections: kanamycin, paromomycin, streptomycin, and possibly gentamicin.
Pregnancy-Lactation
Interactions
Adverse Effects
Side effects of Gramacidin + Neomycin + Polymixin B (Eye prep) :
Adverse reactions have occurred with the anti-infective components of this product. The exact incidence is not known. Reactions occurring most often are allergic reactions including itching, swelling, and conjunctival erythema . More serious hypersensitivity reactions, including anaphylaxis, have been reported rarely.
Local irritation on instillation has also been reported.
Mechanism of Action
Gramicidin is an antibacterial which is too toxic to be used systemically, so it is rather used as a topical and ophth agent and in combination with other antibacterials (neomycin and polymixin B) and also with corticosteroids.
Neomycin is an aminoglycoside antibiotic. It binds to 30S ribosomal subunits of bacterial ribosome thus inhibiting protein synthesis and generating errors in genetic code transcription causing cell death. It acts against many gram-negative aerobes and some gram-positive aerobes. It lacks activity against fungi, viruses and most anaerobic bacteria.
Polymyxin B disrupts the bacterial cytoplasmic membrane of mostly gm-ve organisms allowing leakage of intracellular constituents by binding to membrane phospholipids.