neomycin topical

Action and Spectrum

Actions and Spectrum: 

Actions: 

Neomycin is a wide spectrum aminoglycoside antibiotic obtained from Streptomyces fradiae. 

It is most effective against gram negative bacteria and few gram-positive bacteria. It is known to be a complex consisting of A, B, C components. Framycetin i.e., Neomycin B is the most effective component of neomycin. Neomycin acts by binding to the ribosomes of bacteria thereby inhibiting protein synthesis that is important for the growth of bacteria. 

Spectrum: 

Neomycin possess good spectrum of antibacterial activity against gram-positive and gram-negative bacteria. 

Drug Interaction

Adverse Reaction

Frequency not defined. 

When applied topically, neomycin has low sensitizing potential. Some rashes might occur. Though it is applied topically to burns, ulcers, chances of causing severe ototoxicity, nephrotoxicity and respiratory paralysis are high. Compared the streptomycin neomycin can block the neuromuscular activity by three-four times than streptomycin. 

Black Box Warning

Black Box Warning: 

For External Use only, do not use in the eyes 

Contraindication / Caution

Contraindication/Caution: 

Contraindications 

• Rashes 
• Irritation 
• Difficulty in hearing (rare) 

Cautions 

• Muscle paralysis can occur when applied to serous cavities(peritoneum)  
• Impaired renal function 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA pregnancy category: Not assigned 

Breastfeeding warnings:  

There is not enough data to study the excretion of drug in breast milk. 

Pregnancy category: 

Category A: Studies that were well-controlled and met expectations revealed no risk to the foetus `in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the foetus in animal experiments.   

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 is an aminoglycoside antibiotic effective mostly against gram negative and gram-positive bacteria. It is a polybasic, water-soluble substance that is heat sensitive.  

Pharmacodynamics: 

By binding to the 30S unit of ribosome of bacteria, neomycin inhibits the protein synthesis of the corresponding bacteria and inhibits the growth thereby reducing the infection. On continuous administration resistance to neomycin can be observed. Due to its poor gastrointestinal tract absorption, it is used as intestinal antiseptic.  

Pharmacokinetics: 

Absorption 

Gastrointestinal absorption of the drug is poor. Systemic toxicity can be seen in patients with kidney and liver damage.  

Distribution 

Only minute fraction of neomycin absorbed is distributed into tissues. But with repetitive doses, its concentration in blood can be increased. Protein binding is also noted to be low i.e., between 0-30%. 

Metabolism 

As the systemic absorption is limited, metabolism study data is restricted. 

Elimination and Excretion 

Small portions of absorbed drug is eliminated through kidneys. The unchanged drug is excreted through faeces. 

Adminstartion

Administration: 

Apply on the affected area of the skin in small quantity. Avoid applying on bites due to animals, deep wounds etc. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: neomycin  

Why do we use neomycin? 

Topical preparations of neomycin are used in the treatment of wound infections, ulcers on the skin and for the treatment of superficial skin infections. It is also used as first aid in treatment of infections due to burns, minor cuts etc.