Neomycin; polymyxin B; gramicidin is a combination of antimicrobial agents in ophthalmic preparations to treat ocular bacterial infections. It may also be used as prophylaxis when there is a risk of infection. Neomycin is an aminoglycoside antibiotic derived from cultures of Streptomyces fradiae. Polymyxin B is a polypeptide antibiotic derived from a strain of Bacillus polymyxa. Gramicidin is a mixture of three pairs of antimicrobials (gramicidin A, B, and C) and is produced by growth of a strain of Bacillus brevis. Neomycin is active against many gram-positive and gram-negative organisms; polymyxin B against a variety of gram-negative organisms; and gramicidin against a variety of gram-positive organisms. Combining these antimicrobials provides an overlapping coverage against a wide range of gram-positive and gram-negative bacteria, including streptococci. The FDA approved neomycin; polymyxin B; gramicidin ophthalmic solution in June 1968.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Ophthalmic Administration
-For ophthalmic use only. Do not give by injection or orally.
-Instruct patient on proper instillation of eye solution.
-Wash hands before and after use. Tilt the head back slightly and pull the lower eyelid down with the index finger. Squeeze one drop into the conjunctival sac and gently apply pressure to the inside corner of your eye for 1 minute; this helps stop the liquid from draining down your tear duct. If you are prescribed more than 1 drop in the same eye, wait about 5 minutes between each drop.
-Avoid contamination. Do not touch the tip of the dropper to the eye, fingertips, or other surface.
-Patients should wait at least fifteen (15) minutes after instilling the eye solution before inserting contact lenses.
-Do not share drops between patients.
Adverse reactions to neomycin; polymyxin B; gramicidin ophthalmic solution are usually related to instillation and/or allergic sensitization. Temporary blurred vision and ocular irritation may occur on instillation. Allergic sensitization reactions typically include ocular pruritus, swelling, and conjunctival erythema. Anaphylactoid reactions and other more serious hypersensitivity reactions have rarely been reported. Neomycin has been associated with skin sensitization. Sensitivity is more common with chronic use on inflamed skin, but may also occur with ophthalmic administration and with topical administration to the eyelids. Patients have reported allergic contact hypersensitivity. The manifestation of the sensitization to neomycin is usually low-grade erythema with swelling, dry scaling, and pruritus, or it may manifest as a failure to heal. Periodic examinations for these symptoms are advisable and the patient should discontinue treatment if they are observed. These symptoms regress quickly upon withdrawing the medication. Neomycin may also cause mast cell degranulation and histamine release.
Superinfection may occur after use of neomycin; polymyxin B; gramicidin ophthalmic solution. Overgrowth of nonsusceptible organisms, including fungi, may occur.
Neomycin; polymyxin B; gramicidin is contraindicated in patients who are allergic to any of the components, including patients with aminoglycoside hypersensitivity, neomycin hypersensitivity, polymyxin hypersensitivity, or gramicidin hypersensitivity. Signs and symptoms of sensitization to topical antibiotics are usually itching, reddening, and edema of the conjunctiva and eyelid. However, sensitization may manifest as failure to heal. Patients should be monitored for the development of hypersensitivity, and the patient should discontinue treatment if signs or symptoms are observed. Long-term use may place the patient at risk to develop hypersensitivity. Patients should avoid products containing these antibiotics after the development of a hypersensitivity reaction. Cross-reaction may occur with such antibiotics as kanamycin, paromomycin, streptomycin, and possibly gentamicin.
Patients who wear contact lenses generally should avoid wearing them while being treated with neomycin; polymyxin B; gramicidin for an ocular infection. If contact lenses must be worn, insert contact lenses at least fifteen (15) minutes after instilling this product.
No well-controlled studies of neomycin; polymyxin B; gramicidin have been conducted in pregnant women. The risk of fetal harm is considered unlikely because systemic absorption of these antibiotics is poor. However, health care providers should be aware that aminoglycosides, such as neomycin, cross the placenta and can cause fetal nephrotoxicity and permanent ototoxicity in infants whose mothers received them during pregnancy. It is not known whether gramicidin or polymyxin B can cause fetal harm during pregnancy. Use during pregnancy only if clearly needed.
Data are limited regarding use of neomycin; polymyxin B; gramicidin during breast-feeding. It should be noted that other aminoglycoside antibiotics have been found in breast milk. While systemic absorption is not significant with the ophthalmic product, the amount of drug that reaches systemic circulation and breast milk may be minimized by applying pressure over the tear duct by the corner of the eye for 1 minute after ophthalmic administration. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA.
The safe and effective use of neomycin; polymyxin B; gramicidin in children has not been established.
Per the manufacturer, this drug has been shown to be active against most strains of the following microorganisms either in vitro and/or in clinical infections: Enterobacter sp., Escherichia coli, Haemophilus influenzae (beta-lactamase negative), Haemophilus influenzae (beta-lactamase positive), Klebsiella sp., Neisseria sp., Pseudomonas aeruginosa, Staphylococcus aureus (MRSA), Staphylococcus aureus (MSSA), Streptococcus pneumoniae, Streptococcus sp.
NOTE: The safety and effectiveness in treating clinical infections due to organisms with in vitro data only have not been established in adequate and well-controlled clinical trials.
For the treatment of superficial ophthalmic infection, including bacterial conjunctivitis, keratitis, keratoconjunctivitis, blepharitis, and blepharoconjunctivitis:
Ophthalmic dosage:
Adults: 1 to 2 drops in the affected eye(s) every 4 hours for 7 to 10 days; up to 2 drops in the affected eye(s) every hour for severe infections.
For ophthalmic surgical infection prophylaxis*:
Ophthalmic dosage:
Adults: 1 drop to the affected eye(s) every 5 to 15 minutes for 5 doses within 1 hour before the start of the procedure. Perioperative antisepsis with povidone-iodine is recommended. Subconjunctival or intracameral antibiotics at the end of the procedure is optional. The necessity of continuing topical antimicrobials postoperatively has not been established.
Maximum Dosage Limits:
-Adults
Maximum dosage information not available.
-Geriatric
Maximum dosage information not available.
-Adolescents
Maximum dosage information not available.
-Children
Maximum dosage information not available; safety and efficacy have not been established.
-Infants
Maximum dosage information not available; safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
No dosage adjustment is needed.
Patients with Renal Impairment Dosing
No dosage adjustment is needed.
*non-FDA-approved indication
There are no drug interactions associated with Neomycin; Polymyxin B; Gramicidin products.
Neomycin; polymyxin B; gramicidin is an ophthalmic solution for treating superficial infections of the external eye. The combined action of neomycin; polymyxin B; gramicidin is bactericidal.
-Neomycin sulfate: Neomycin inhibits bacterial protein synthesis through irreversible binding to the 30 S ribosomal subunit of susceptible bacteria. Neomycin is actively transported into the bacterial cell where it binds to receptors present on the 30 S ribosomal subunit. This binding interferes with the initiation complex between the messenger RNA and the subunit. As a result, abnormal, nonfunctional proteins are formed due to misreading of the bacterial DNA. Eventually, susceptible bacteria die because of the lack of functional proteins.
-Polymyxin B sulfate: Polymyxin B binds to gram-negative bacterial cell membrane phospholipids. This binding destroys bacterial membranes with a surface detergent-like mechanism and increases the permeability of the cell membrane, which results in loss of metabolites essential to bacterial existence. Polymyxin B has no in vitro activity against gram-positive organisms or fungi. The in vivo activity of polymyxin B against Pseudomonas aeruginosa is decreased by the presence of divalent cations such as calcium, which is believed to interfere with the binding of the drug to the cell membrane.
-Gramicidin: Gramicidin is bactericidal against a variety of gram-positive bacteria. It increases the permeability of the bacterial cell membrane to inorganic cations. Gramicidin binds to bacterial cell membranes and forms a network of channels through the normal lipid bilayer.
Neomycin; polymyxin B; gramicidin combination products are applied topically to the eye.
-Route-Specific Pharmacokinetics
Other Route(s)
Ophthalmic Route
Animal data suggest neomycin is absorbed into the aqueous humor, especially if the cornea is abraded. It is not known whether gramicidin or polymyxin B are absorbed into aqueous humor. Systemic absorption of these antibiotics after topical application to the eye is not likely to be significant.