Gentamicin 0.3% w/v

Category- Allopathy

Medicine Highlights

Gentamicin Uses 

Gentamicin belongs to the Macrolide antibiotic class. It is used to treat serious bacterial infections such as: 

1. Bacterial conjunctivitis (pink eye) 
2. Eyelid infections (blepharitis) 
3. Corneal infections (keratitis) 
4. Eye infections after injury or surgery 

Directions for use

1. Take this medicine exactly as prescribed by your doctor, consistently at the same time each day.
2. Do not stop taking this medicine without your doctor’s approval, even if you feel better.
3. If you miss a dose, take it as soon as you remember, unless it’s close to your next dose; then skip the missed one. 

Gentamicin side effects

More Common

1. Mild burning or stinging in the eye 
2. Eye irritation or redness 
3. Itching 
4. Blurred vision (temporary) 
5. Watery eyes    

Less common 

1. Severe eye pain or swelling 
2. Worsening redness or discharge 
3. Rash or allergic reaction around the eyes 
4. Vision changes 

How Gentamicin works

Gentamicin works by stopping bacteria from making proteins, which are essential for bacterial growth and survival. As a result, it stops the bacteria from growing and prevents the infection from spreading. 

Safety Measures and Warning 

Allergy/Hypersensitivity

 If you are allergic to this medicine, taking it can cause serious reactions like rashes, swelling, or trouble breathing. Stop the medicine immediately and get medical help. 

Hearing or balance problems

People with hearing or balance issues should use this medicine under doctor supervision, as it can damage the inner ear, causing hearing loss or dizziness. 

Pregnancy

If you are pregnant, inform your doctor as Gentamicin should be used only if clearly needed; safety for the baby is not fully established.   

Breastfeeding

If you are breastfeeding, inform your doctor, since Gentamicin may pass into breast milk and affect the baby.  

Gentamicin Interaction with other Medicines

Avoid taking Gentamicin with the following medicines, as it may increase or decrease the desired effect, or in worse cases, it could be fatal:

Gentamicin Interaction with Food Products

Gentamicin does not have significant food interactions. 

Storage   

1. The medicine should be stored at room temperature.
2. Keep away from sunlight and moisture.
3. Keep away from the reach of children. 

Gentamicin Chemical Structure

IUPAC (International Union of Pure and Applied Chemistry)/ Chemical name

Gentamicin: 2-[4,6-diamino-3-[3-amino-6-[1-(methylamino)ethyl]oxan-2-yl]oxy-2-hydroxycyclohexyl]oxy-5-methyl-4-(methylamino)oxane-3,5-diol 

Intake routine/cycle 

Daily Dose

Take Gentamicin exactly as your doctor recommends. The dose may change based on your condition and how well you respond. Do not take more than prescribed without consulting your doctor.

Missed Dose

If you forget to take your medicine, take the medication as soon as you remember. If it’s nearly time for your next dose, skip the missed one and continue with your regular schedule. Always consult the doctor before making any changes to your dosage.

Overdose

Do not use Gentamicin eye drops more often or for longer than prescribed, as overuse may increase the risk of eye irritation, redness, swelling, or blurred vision. Seek medical attention immediately if you experience severe eye pain, worsening symptoms, or signs of an allergic reaction. 

Gentamicin Summary

Gentamicin 0.3% eye drops are an antibiotic used to treat bacterial eye infections such as conjunctivitis, eyelids, and corneal infections. They work by stopping bacteria from growing, helping clear redness, discharge, and irritation. Common side effects include mild burning, stinging, redness, or watery eyes, while serious reactions like eye swelling, worsening pain, or vision changes need medical attention. It should not be used by people allergic to gentamicin or those with viral or fungal eye infections and should be used cautiously during pregnancy or breastfeeding only if prescribed by a doctor.   

FAQ’s 

What are the side effects of gentamicin? 

Common side effects include pain at the injection site, nausea, vomiting, rash, or itching. Serious side effects may include kidney problems, hearing loss or balance issues, allergic reactions, and muscle weakness.  

What is the drug class of gentamicin? 

Gentamicin belongs to the aminoglycoside antibiotic class. 

What is gentamicin used for? 

Gentamicin is used to treat serious bacterial infections in blood, respiratory, urinary tract, skin and soft tissue and bone and joint infections 

What is the mechanism of action of gentamicin? 

Gentamicin works by stopping bacteria from making proteins, which are essential for bacteria’ growth and survival. As a result, it stops the bacteria from growing and prevents the infection from spreading. 

Reference

1. Chaves BJ, Tadi P. Gentamicin [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2023. Available from 
2. PubChem. Gentamicin [Internet]. Pubchem. PubChem; 2019. Available from 
3. Gentamicin (Ophthalmic Route) Description and Brand Names – Mayo Clinic [Internet]. Mayoclinic.org. 2024. Available from 
4. Genticin (Gentamicin 0.3% w/v) Eye/Ear Drops – Summary of Product Characteristics (SmPC) – (emc) [Internet]. www.medicines.org.uk. Available from  

Pranathi Chintaluri

Pranathi is a final year Pharm D student at Chalapathi Institute of Pharmaceutical Sciences. She loves learning and applying her knowledge in pharmacy and has a passion for writing, which allows her to express ideas clearly and creatively. She enjoys combining her technical skills with her love for writing and communication to make a meaningful impact. Currently she is working on a research paper about “Consanguineous marriages and its impact on children’s health” which will be published by the end of 2025.