Bacitracin ophthalmic

Most polymyxin B sold for human use in the United States is in dermatological, otic, and ophthalmic preparations that usually contain one or more other spectmm extending antibacterials such as bacitracin, neomycin sulfate [1404-04-2], C23H4gNg023, linear gramicidin, oxytetracycline [79-57-2],... 

Bacitracin given parenteraHy is sufftciendy nephrotoxic that it is rarely used in human medicine for other than topical indications (80). Thus safe and effective use, especially as the zinc salt, is limited almost completely to ointments, sprays, and solutions for skin and ophthalmic use in concentrations of 250 to 1000 units per milliliter. Bacitracin is only rarely skin sensitizing. As in the case of polymyxin, bacitracin is usually combined with other antibiotics to enlarge its spectmm of activity, or with corticoids or analgesics to reUeve pain or itching. 

Although tyrothricia is too toxic for parenteral therapy, it was formerly sold in the United States as oral lo2enges. Modem tyrothricin formulations are composed of 70—80% tyrocidines and 30—20% linear gramicidins. Tyrocidines are not as active as linear gramicidins and are too toxic for any therapeutic use by themselves. The bactericidal linear gramicidins are used in the United States solely as an ophthalmic solution in combination with polymyxin B sulfate and neomycin sulfate. The linear gramicidin is used in this aqueous product as a substitute for bacitracin, which lacks stabiUty under such conditions. 

AK-Fbly-Bac Ophthalmic Ointment—polymyxin B sulfate, bacitracin zinc... 

Rx with chloramphenicol (Chloromycetin/HC suspension—ophthalmic) with neomycin and polymyxin B (Cortisporin Otic, Drotic, Otocort—otic) with neomycin, polymyxin B, and bacitracin (Cortisporin Ointment, Neotricin HC—ophthalmic) with oxytetracycline (Terra-Cortril—ophthalmic) with urea (Carmol HC)... 

Topical ophthalmic preparations containing bacitracin (Tables 11-5, 11-6, and 11-7) are effective for treatment of superficial eye infections. Bacitracin is especially useful for treating staphylococcal blepharitis, because most staphylococci remain sensitive to this antibiotic (see Table 11-1). 

Bacitracin is bactericidal for most gram-positive organisms, especially Staphylococcus and Streptococcus species. It is particularly useful when combined with polymyxin B in an ophthalmic ointment. Bacitracin-polymyxin B ointment (Polysporin) provides broad-spectrum antibacterial activity for patients who require nighttime therapy or who are not comfortable with eyedrops. Bacitracin-polymyxin B ointment is particularly effective in the pediatric population because of the high incidence of Streptococcus infection.The usual dose frequency is three to four times daily.Although adverse events are rare, hypersensitivity reactions can occur. Additionally, bacitracin can sometimes be uncomfortable. 

Topical corticosteroids are used in cases of exacerbation and should be applied sparingly to the affected area. Hydrocortisone 1% twice a day or dexamethasone 0.1% applied to the periorbital area helps to relieve symptoms during these periods. Secondary infection manifested as blepharitis or keratoconjimctivitis should be treated with topical ophthalmic antibiotic ointments such as bacitracin or erythromycin.Topical antihistamines, NSAIDs, or mast cell stabilizers can be used to control itching, and topical steroids are sometimes required to treat severe keratoconjunctivitis associated with the atopic response. Because of side effects, steroids are not indicated for longterm use. 

Thiomersal, a mercury derivative of thiosaUcylic acid, is a preservative used in several types of consumer products, including cosmetics, ophthalmic and otolaryngological medications, and vaccines. In a retrospective study in 574 patients, people who were allergic to thiomersal were more likely to be allergic to bacitracin (10). 

Neomycin is not usually administered parenter-ally to animals because of nephrotoxicity and ototoxicity. Only 3% of a dose of neomycin is absorbed following p.o. administration it is, therefore, used in the therapy of coliform enteritis in small and large animals. It is available as tablets, boluses and water additives, in many different combinations with antibiotics, corticosteroids and anticholinergic agents. It can also be used to decrease nitrogenous waste production by the normal gastrointestinal flora in animals with hepatic encephalopathy. Neomycin is not absorbed through the skin, so it is frequently utilized as the antibacterial constituent in ophthalmic formulations (especially in combination with bacitracin and polymyxin B) and in preparations for the treatment of otitis externa in small animals. 

Note Bacitracin is supplied in many forms and vehicles Intramuscular topical, ophthalmic, otic, aerosols, for irrigations. Many Bacitracin ointments are combinations with Neomycin and Polymyxin B. 

The bacitracin zinc and polymyxin B sulfate ophthalmic ointment USP is a sterile antimicrobial ointment formulated for ophthalmic use. Bacitracin zinc is the zinc salt of bacitracin, a mixture of related cyclic polypeptides (mainly bacitracin A) produced by the growth of an organism of the lichenlformis group of Bacillus subtilis var Tracy. It has a potency of not less than 40 bacitracin units per milligram. Polymyxin B sulfate is the sulfate salt of... 

The neomycin and polymyxin B sulfates and bacitracin zinc ophthalmic ointment is a sterile antimicrobial ointment for ophthalmic use. Each gram contains neomycin sulfate... 

BACITRACIN ZINC/POLYMYXIN B SULFATE (Polysporln Ophthalmic ointment)... 

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