Indications
Gramicidin is an antibiotic used only on the surface of the body, never by mouth or injection. It is found in combination products with Neomycin and Polymyxin B (and sometimes a steroid) as eye drops, ear drops, creams and ointments. These are used to treat bacterial infections of the eye (such as conjunctivitis), the outer ear, and the skin, including infected cuts, grazes and minor burns.
How It Works
Gramicidin forms tiny channels in the outer membrane of bacteria, causing them to leak and die. It mainly acts against Gram-positive bacteria, while Neomycin and Polymyxin B in the same product cover many other bacteria, so together they treat a wide range of surface infections.
Dosage and Administration
Use as directed on the label or by your doctor. Eye drops: usually 1 to 2 drops into the affected eye 2 to 4 times daily (more often in severe infections at first). Ear drops: usually 2 to 3 drops into the ear 3 to 4 times daily. Skin cream: apply a thin layer to the affected area 2 to 4 times daily. Use for the full course, usually 7 days, and do not use for longer than 7 to 10 days unless advised.
Interactions
Absorption into the body is minimal, so interactions are unlikely. Avoid using other eye or ear products at the same time without advice. Large areas of broken skin treated with Neomycin-containing products, together with other medicines that can harm the kidneys or hearing (such as Gentamicin or Furosemide), may increase the risk of side effects.
Contraindications
Do not use if you are allergic to Gramicidin, Neomycin, Polymyxin B or other ingredients. Ear drops must not be used if the eardrum is perforated (has a hole), because Neomycin can damage hearing.
Side Effects
- Brief stinging or burning when applied
- Itching, redness or swelling (possible allergy, especially to Neomycin)
- Blurred vision for a short time after eye drops
- With long use, growth of resistant germs or fungi
Get urgent medical help if you notice spreading rash, swelling of the eyelids, face or throat, difficulty breathing, worsening eye pain or loss of vision, or new hearing loss, ringing in the ears or dizziness after using ear drops.
Pregnancy and Lactation
Topical use is generally considered acceptable for short periods, as very little enters the body. Ask your doctor before use, especially for large areas of skin or long courses.
Precautions and Warnings
Do not touch the dropper tip to the eye, ear or any surface. Do not wear contact lenses during an eye infection. Stop and see a doctor if the infection does not improve within a few days or gets worse. Do not use on large areas of damaged skin. Products that also contain a steroid should not be used on viral or fungal infections.
Overdose
Overdose is unlikely with topical use. If swallowed, seek medical advice.
Therapeutic Class
Topical antibiotic (polypeptide); used in combination anti-infective eye, ear and skin preparations.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children; do not freeze. Discard eye and ear drops 4 weeks after opening.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.