Antibiotic eye drops are given to treat infection or to prevent infection after eye procedures. Different types of drops are used for different conditions. Antibiotic eye drops are available only as prescription medications. It is important to see your doctor and not use old medications to treat eye conditions, because even though eye conditions may seem the same, they may need entirely different types of treatment.
Bacteriocidal eye drops kill bacteria. Some antibiotics, such as penicillin and tetracycline, do not penetrate the cornea (the outside layer of the eye) well, and are rarely used in antibiotic eye drops. Commonly used bacteriocidal ophthalmic drops include aminglycosides, which are effective against gram-negative bacteria, such as pseudomonas. Pseudomonas often contaminate eye products, such as mascara and contact lenses. Bacteriocidial ophthalmic drops include amikacin, gentamycin, neomycin and tobramycin, according to "Fundamentals for Ophthalmic Technical Personnel." Other frequently used bacteriocidal antibiotics are ciprofloxacin, erythromycin, gatafloxin, monofloxacin, ocufloxacin, according to Eye Drops Info.
Bacteriostatic eye drops do not kill bacteria; they just stop bacteria from multiplying. These are often given to treat bacterial conjunctivitis, according to "Fundamentals for Ophthalmic Technical Personnel," and include sulfonamides, such as AK-Sulf, Sulamyd, Bleph 10 and Gantrisin.
Some antibiotic drops contain an antibiotic in combination with another drug, such as a steroid. By accomplishing two purposes, combination drugs save patients from having to put more drops in their eyes. Some examples of combination drops are: maxitrol--a combination of dexamethasone (a steroid), neomycin and polymixin b (both antibiotics); tobradex--a combination of tobramycin (an antibiotic) and dexamethasone; and cortisporin--a combination of hydrocortisone (a steroid) and antibiotics neomycin, bacitracin and polymixin b, according to "Fundamentals for Ophthalmic Technical Personnel."