Sulphacetamide 20% w/v

Category- Allopathy

Medicine Highlights

Sulphacetamide Uses  

Sulphacetamide is an antibiotic medicine that is used to kill bacteria. It helps treat conditions such as: 

1. Conjunctivitis (redness and irritation of the eye) 
2. Superficial eye infections caused by susceptible bacteria such as blepharitis       

Directions for use

1. Take this medicine exactly as prescribed by your doctor, 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 forget to take this medicine, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose.  

Sulphacetamide side effects 

More Common  

1. Mild burning or stinging in the eye 
2. Temporary blurred vision after application 
3. Eye irritation, redness, or itching 
4. Watery eyes   

Less Common

1. Severe allergic reactions (swelling, rash, itching) 
2. Blood-related problems with long-term or repeated use (very rare)      

How Sulphacetamide works 

Sulphacetamide works by blocking the production of folic acid in bacteria, which is essential for their growth and multiplication. Without folic acid, bacteria cannot make DNA and proteins, so they stop growing and eventually die, helping to clear the infection. 

Safety Measures and Warning 

Allergy/Hypersensitivity

 Inform your doctor about any history of allergic reactions, as sulphacetamide should not be used in people allergic to sulfonamide drugs. Using it may cause itching, redness, swelling, rash, or severe allergic reactions. 

Severe Eye Conditions

Inform your doctor if you have any serious eye conditions or infections other than bacterial, as sulphacetamide should not be used in such cases. It may worsen the condition or delay appropriate treatment. 

Sulphacetamide Interaction with Food Product

Since these drops are applied directly to the eye, they do not have any known food or drink interactions. You can eat and drink normally while using them. However, always wash your hands before and after applying the drops to avoid accidental ingestion. 

Sulphacetamide Interaction with Other Medicines

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

Sulphacetamide Chemical Structure

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

Sulphacetamide: N-(4-aminophenyl)sulfonylacetamide 

Intake routine/cycle

Daily dose

Take Sulphacetamide 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 more than the prescribed number of drops in your eyes. Overuse may cause severe irritation, burning, redness, swelling, or blurred vision. If you notice any of these symptoms or severe discomfort, rinse your eyes with clean water and seek medical attention immediately. 

Storage

1. Store the medicine at room temperature 
2. Keep away from sunlight and moisture 
3. Keep out of reach of children 

Sulphacetamide Summary

Sulphacetamide 20% w/v eye drop is a sulfonamide antibiotic used to treat bacterial eye infections such as conjunctivitis, blepharitis, and other superficial ocular infections. It works by blocking the production of folic acid in bacteria, which prevents bacterial growth and helps clear the infection. Common side effects may include mild burning, stinging, redness, or temporary blurred vision.  

People who are allergic to this medicine or have a blood or bone marrow disorders, should use this medicine under doctor supervision. Applied externally, they have no known food interactions, but hands should be washed before and after use. The drops should be used exactly as prescribed by a doctor to avoid irritation or overdose. 

FAQ’s

What are the uses of Sulphacetamide 20% eye drops? 

Sulphacetamide 20% eye drops are used to treat bacterial eye infections such as conjunctivitis (pink eye), blepharitis (infected eyelids), and other superficial eye infections caused by susceptible bacteria. They help reduce redness, irritation, and discharge by stopping the bacteria from growing. 

How does Sulphacetamide eye drops work? 

Sulphacetamide works by blocking the production of folic acid in bacteria, which is essential for their growth and multiplication. Without folic acid, bacteria cannot make DNA or proteins, so they stop growing and die, helping clear the eye infection. 

Reference 

1. https://www.facebook.com/Drugscom. Sulfacetamide Sodium Ophthalmic Dosage Guide + Max Dose, Adjustments [Internet]. Drugs.com. 2025. Available from 
2. Pediatriconcall.com. 2025 [cited 2026 Jan 29]. Available from 
3. Hannemann K, Gourley A. Bleph-10 (sulfacetamide): Uses, Side Effects, Dosage & More [Internet]. GoodRx. 2022 [cited 2026 Jan 29]. 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.