What are the ingredients in Polytrim (polymyxin B sulfate and trimethoprim)?

From the FDA Drug Label

DESCRIPTION Trimethoprim Sulfate and Polymyxin B Sulfate Ophthalmic Solution is a sterile antimicrobial solution for topical ophthalmic use. Trimethoprim sulfate, 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine sulfate (2:1), occurs as a white, odorless, crystalline powder with a molecular weight of 678. 72. The structural formula is as follows: Polymyxin B sulfate is the sulfate salt of polymyxin B1 and B2 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 anhydrous basis The structural formula is as follows: Each mL contains: Actives: Trimethoprim Sulfate equivalent to Trimethoprim 1 mg (0.1%) and Polymyxin B Sulfate 10,000 units. Preservative: Benzalkonium Chloride 0.04 mg (0.004%). Inactives: Sodium Chloride, Sulfuric Acid and Sodium Hydroxide may be added to adjust pH (3.0 to 5.5), and Purified Water USP. Contains: Actives:polymyxin B sulfate 10,000 units/mL; trimethoprim sulfate equivalent to 1 mg/mL. Preservative:benzalkonium chloride 0.04 mg/mL. Inactives:purified water; sodium chloride; and sulfuric acid. May also contain sodium hydroxide for pH adjustment.

The ingredients in Polytrim (polymyxin B sulfate and trimethoprim) are:

• Actives:
  • Trimethoprim sulfate (equivalent to 1 mg trimethoprim)
  • Polymyxin B sulfate (10,000 units)
• Preservative:
  • Benzalkonium chloride (0.04 mg)
• Inactives:
  • Sodium chloride
  • Sulfuric acid
  • Purified water
  • Sodium hydroxide (may be added for pH adjustment) 1 2

From the Research

Polytrim is an antibiotic eye drop medication that contains two active ingredients: polymyxin B sulfate and trimethoprim. This combination provides broad-spectrum antimicrobial coverage against many common eye infection-causing bacteria. The ingredients in Polytrim work together to disrupt bacterial cell membranes and block bacterial production of folate, which is essential for bacterial growth and reproduction. The standard dosage is usually one drop in the affected eye(s) every three to four hours for 7-10 days, though you should always follow your doctor's specific instructions 3. When using Polytrim, it is essential to avoid touching the dropper tip to any surface to prevent contamination, wash hands before and after application, and complete the full course of treatment even if symptoms improve quickly to ensure the infection is completely eliminated. Some studies have shown that Polytrim is effective against a wide range of bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa 4. However, it is crucial to note that antibiotic resistance is a growing concern, and the efficacy of Polytrim may vary depending on the specific bacterial strain and the patient's individual circumstances 3, 4. In general, Polytrim is a useful treatment option for bacterial conjunctivitis and other superficial eye infections, but it is essential to use it judiciously and follow the recommended dosage and administration guidelines to minimize the risk of antibiotic resistance and ensure optimal treatment outcomes. Key points to consider when using Polytrim include:

• The importance of completing the full course of treatment to ensure the infection is completely eliminated
• The need to avoid touching the dropper tip to any surface to prevent contamination
• The importance of washing hands before and after application
• The potential for antibiotic resistance and the need to use Polytrim judiciously
• The efficacy of Polytrim against a wide range of bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa 3, 4.