Action and Spectrum

Actions and Spectrum: 

neomycin/polymyxin B/gramicidin ophthalmic is a combination antibiotic eye drop that contains three active ingredients: neomycin, polymyxin B, and gramicidin. Each of these antibiotics works by targeting and killing bacteria.  

neomycin: This antibiotic belongs to the aminoglycoside class and works by binding to bacterial ribosomes, preventing protein synthesis and thereby leading to cell death. neomycin is active against many gram-negative and gram-positive bacteria, including Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. 

Polymyxin B: This antibiotic belongs to the polymyxin class and works by binding to the bacterial cell membrane and disrupting its integrity, leading to leakage of intracellular contents and, thereby, cell death. polymyxin B is active against gram-negative bacteria, including Pseudomonas aeruginosa and some strains of Enterobacteriaceae. 

gramicidin: This antibiotic is a cyclic peptide that works by forming pores in the bacterial cell membrane, disrupting membrane integrity and leading to cell death. gramicidin is active against gram-positive bacteria, including Streptococcus pneumoniae and Staphylococcus aureus. 

These three antibiotics provide broad-spectrum coverage against many bacteria that can cause eye infections, including gram-positive and gram-negative bacteria. The combination of neomycin, polymyxin B, and gramicidin is often used to treat bacterial conjunctivitis, blepharitis, and other eye and surrounding tissue infections. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Itching, swelling, and conjunctival erythema 

Vesicular and maculopapular dermatitis 

Urticaria 

Hypersensitivity 

Local transient irritation 

Angioneurotic edema 

Black Box Warning

Contraindication / Caution

Contraindications/caution: 

Contraindications: 

neomycin/polymyxin B/gramicidin ophthalmic should not be used in patients with a known hypersensitivity to any of the components of the medication, including neomycin, polymyxin B, gramicidin, or any other related antibiotics. Patients with a history of hypersensitivity to aminoglycosides or polymyxins should also avoid using this medication.  

Additionally, neomycin/polymyxin B/gramicidin ophthalmic should not be used in patients with a viral or fungal eye infection, as it is only effective against bacterial infections. Patients with a perforated eardrum or those who are pregnant or breastfeeding may also be advised to avoid using this medication, as it can potentially cause harm to the fetus or infant.  

Patients with a history of kidney disease or hearing problems should use neomycin/polymyxin B/gramicidin ophthalmic cautiously, as neomycin and polymyxin B can be absorbed into the bloodstream and cause renal toxicity or ototoxicity. Patients taking other medications that can cause nephrotoxicity or ototoxicity should also be monitored closely while using this medication. 

Caution: 

neomycin/polymyxin B/gramicidin ophthalmic should be used with caution in patients with kidney disease or hearing problems, as the neomycin and polymyxin B components of the medication can be absorbed into the bloodstream and cause renal toxicity or ototoxicity. Patients taking other medications that can cause nephrotoxicity or ototoxicity should also be monitored closely while using this medication. 

Patients wearing contact lenses should remove them before using neomycin/polymyxin B/gramicidin ophthalmic and wait at least 15 minutes before reinserting them, as the medication may contain preservatives or other ingredients that can damage contact lenses. 

neomycin/polymyxin B/gramicidin ophthalmic may cause temporary blurring of vision or other visual disturbances after application. Patients should avoid driving or operating machinery until their vision fully reaches normal. 

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available 

Lactation: Excretion of the drug in human breast milk is unknown 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.   

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

neomycin/polymyxin B/gramicidin ophthalmic is a combination medication that contains three different antibiotics: neomycin, polymyxin B, and gramicidin. Each of these antibiotics has its unique pharmacology: 

neomycin is an aminoglycoside antibiotic poorly absorbed from the gastrointestinal tract. It has limited systemic absorption when applied topically to the eye. It is primarily eliminated unchanged in the urine. Its half-life is approximately 2 to 3 hours in patients with normal renal function. 

polymyxin B is a polypeptide antibiotic that is also poorly absorbed from the gastrointestinal tract and has limited systemic absorption when applied topically to the eye. It is primarily eliminated unchanged in the urine. Its half-life is approximately 1 to 2 hours in patients with normal renal function.  

gramicidin is a polypeptide antibiotic not absorbed systemically when applied topically to the eye. Proteolytic enzymes rapidly inactivate it and have a short duration of action. 

When applied topically to the eye, neomycin/polymyxin B/gramicidin ophthalmic provides broad-spectrum coverage against many bacterial pathogens that can cause eye infections, including conjunctivitis, keratitis, and blepharitis. The three antibiotics work synergistically to provide greater efficacy than any antibiotics alone. However, because the medication is applied topically to the eye, systemic exposure and the potential for systemic side effects are minimal. 

Pharmacodynamics: 

The pharmacodynamics of neomycin/polymyxin B/gramicidin ophthalmic are primarily based on the individual pharmacodynamics of each of the three antibiotics in the combination. 

neomycin works by binding to the 30S ribosomal subunit of bacterial cells, inhibiting protein synthesis and ultimately leading to bacterial cell death. Polymyxin B works by disrupting the bacterial cell membrane, causing leakage of intracellular contents and ultimately leading to bacterial cell death. Gramicidin works by forming channels in the bacterial cell membrane, disrupting ion gradients, and leading to bacterial cell death. 

The three antibiotics work synergistically to provide broad-spectrum coverage against many gram-positive and gram-negative bacterial pathogens. The combination is particularly effective against Staphylococcus aureus, Streptococcus pneumoniae, and Pseudomonas aeruginosa, common causes of bacterial eye infections. 

The pharmacodynamics of neomycin/polymyxin B/gramicidin ophthalmic are primarily limited to the eye’s surface, where the medication is applied. The combination is minimally absorbed systemically; systemic side effects are rare. However, it is essential to use the medication as directed to avoid the development of resistant bacterial strains. 

Pharmacokinetics: 

Absorption 

When applied topically to the eye, the medication is minimally absorbed systemically. However, a small amount of the medication may be absorbed into the systemic circulation through the conjunctiva. 

Distribution 

The distribution of the medication is limited to the surface of the eye and surrounding tissues. The three antibiotics in the combination have different binding characteristics, with neomycin and polymyxin B binding primarily to plasma proteins and gramicidin having a high affinity for cell membranes. 

Metabolism 

The three antibiotics in the combination are not extensively metabolized and are primarily eliminated unchanged in the urine. 

Elimination and Excretion 

neomycin and polymyxin B are eliminated primarily by the kidneys. At the same time, gramicidin is rapidly degraded by proteolytic enzymes in the body. 

Adminstartion

Administration: 

neomycin/polymyxin B/gramicidin ophthalmic is an ophthalmic antibiotic combination medication for treating bacterial eye infections. It is typically available in the form of eye drops or ointment.  

The medication should be administered as directed by a healthcare professional or as indicated on the medication label. Generally, the recommended dose is one to two drops or a small amount of ointment placed in the affected eye(s) every four hours or as directed by the healthcare provider. The course of treatment may vary depending on the response to treatment and the severity of the infection.  

Before using the medication, hands should be washed thoroughly with soap and water. The cap should be removed from the bottle, and the head should be tilted back while pulling down the lower eyelid to create a small pocket. One or two drops or a small amount of ointment should be placed in the pocket. The eye should be closed for a few seconds to allow the medication to spread evenly across the eye. The process should be repeated for the other eye, if necessary. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: neomycin/polymyxin B/gramicidin ophthalmic 

Why do we use neomycin/polymyxin B/gramicidin ophthalmic? 

neomycin/polymyxin B/gramicidin ophthalmic is an antibiotic combination medication used to treat bacterial eye infections, such as conjunctivitis, keratitis, and blepharitis. It is effective against many gram-positive and gram-negative bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, and Pseudomonas aeruginosa. 

The medication works by inhibiting bacterial growth and killing the bacteria causing the infection. neomycin and polymyxin B disrupt the bacterial cell membrane, while gramicidin interferes with bacterial protein synthesis. 

A healthcare provider typically prescribes this medication, and is available as eye drops or ointments. It should only be used for bacterial eye infections, not viral or fungal infections.