POLYMYXIN B SULFATE AND TRIMETHOPRIM

Polymyxin B sulfate and trimethoprim ophthalmic solution, USP is a sterile antimicrobial solution for topical ophthalmic use. It has pH of 4.0 to 5.5 and osmolality of 270 to 310 mOsm/kg. Chemical Names: Trimethoprim sulfate, 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine sulfate, is a white, odorless, crystalline powder with a molecular weight of 678.72 and the following structural formula: Polymyxin B sulfate is the sulfate salt of polymyxin B 1 and B 2 which are produced by the growth of Bacillus polymyxa (Prazmowski) Migula (Fam. Bacillaceae). It has a potency of not less than 6,000 polymyxin B units per mg, calculated on an anhydrous basis. The structural formulae are: Each mL contains: Actives: polymyxin B sulfate equal to 10,000 polymyxin B units, trimethoprim sulfate (equivalent to trimethoprim 1 mg); Inactives: purified water, sodium chloride. Sulfuric acid and, if necessary, sodium hydroxide may be added to adjust pH (4.0 – 5.5). Preservative: benzalkonium chloride 0.004%. Chem structure chemical structure 2

Polymyxin B sulfate and trimethoprim ophthalmic solution is indicated in the treatment of surface ocular bacterial infections, including acute bacterial conjunctivitis, and blepharoconjunctivitis, caused by susceptible strains of the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus viridans, Haemophilus influenzae and Pseudomonas aeruginosa. 1 1 Efficacy for this organism in this organ system was studied in fewer than 10 infections.

In mild to moderate infections, instill one drop in the affected eye(s) every 3 hours (maximum of 6 doses per day) for a period of 7 to 10 days.

Polymyxin B sulfate and trimethoprim ophthalmic solution is contraindicated in patients with known hypersensitivity to any of its components.

The most frequent adverse reaction to polymyxin B sulfate and trimethoprim ophthalmic solution is local irritation consisting of increased redness, burning, stinging, and/or itching. This may occur on instillation, within 48 hours, or at any time with extended use. There are also multiple reports of hypersensitivity reactions consisting of lid edema, itching, increased redness, tearing, and/or circumocular rash. Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) and anaphylaxis have been reported. Photosensitivity has been reported in patients taking oral trimethoprim. To report SUSPECTED ADVERSE REACTIONS, contact Bausch & Lomb Incorporated at 1-800-553-5340 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .