Fusidic acid is a narrow-spectrum antibiotic active mainly against Gram-positive bacteria—above all Staphylococcus aureus, including MRSA—so its applications cluster around staph and other Gram-positive infections.
Topical / dermatology (largest commercial volume)
Skin and soft-tissue infections: impetigo, folliculitis, furunculosis, infected dermatitis/eczema, infected wounds and burns, erythrasma. Sold as fusidic acid cream/ointment and sodium fusidate ointment, and very heavily as steroid combinations (fusidic acid + betamethasone, + hydrocortisone)—the combination creams are major sellers in your India/Bangladesh/Pakistan/MENA markets.
Ophthalmic
Fusidic acid 1% viscous eye drops for bacterial conjunctivitis and othe...