What is the dosing for Polytrim (polymyxin B sulfate and trimethoprim) ophthalmic solution?

From the Guidelines

Polytrim ophthalmic solution (polymyxin B-trimethoprim) should be dosed at a frequency of no less than 3 to 4 times a day, as lower doses may increase the risk of developing antibiotic resistance, especially in the presence of virulent or indolent organisms or for immunocompromised patients 1. The dosing of Polytrim ophthalmic solution is crucial in treating bacterial keratitis effectively.

• The medication's efficacy depends on maintaining an adequate dosage regimen to prevent subtherapeutic levels, which could lead to antibiotic resistance.
• According to the bacterial keratitis preferred practice pattern, most antibiotic eye drops, including Polytrim, should not be tapered below 3 to 4 times a day 1.
• It is essential to consider the potential risks associated with underdosing, particularly in vulnerable populations such as immunocompromised patients.
• The specific dosing instructions for Polytrim, such as the volume of each dose (e.g., 1 drop) and the maximum number of doses per day, should be followed carefully to ensure optimal treatment outcomes.
• Patients should be advised on proper administration techniques, including tilting the head back, pulling down the lower eyelid, and gently closing the eyes after instillation to facilitate absorption.
• Additionally, patients should be informed about potential side effects, such as temporary stinging or burning, and instructed to seek medical attention if symptoms worsen or do not improve within 72 hours.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Adults: In mild to moderate infections, instill one drop in the affected eye(s) every three hours (maximum of 6 doses per day) for a period of 7 to 10 days. Pediatric Use: Clinical studies have shown Trimethoprim and Polymyxin B Sulfate Ophthalmic Solution to be safe and effective for use in pediatric patients over two months of age. The dosage regimen is the same as for adults. The dosing for Polytrim (polymyxin B sulfate and trimethoprim) ophthalmic solution is:

• One drop in the affected eye(s)
• Every three hours
• Maximum of 6 doses per day
• For a period of 7 to 10 days in adults and pediatric patients over two months of age 2

From the Research

Dosing Information for Polytrim

• The dosing for Polytrim (polymyxin B sulfate and trimethoprim) ophthalmic solution is not explicitly stated in the provided studies.
• However, according to the study 3, trimethoprim-polymyxin B ophthalmic solution was prescribed to children with acute bacterial conjunctivitis, but the dosing frequency is not mentioned.
• In the study 4, polymyxin B sulfate/trimethoprim ophthalmic solution was administered 4 times daily for 7 days, but this study does not provide information on the standard dosing of Polytrim.

Comparison with Other Treatments

• The study 4 compared the speed of clinical efficacy of polymyxin B sulfate/trimethoprim with moxifloxacin ophthalmic solution, and found that moxifloxacin was more effective and faster in reducing symptoms.
• The study 5 discusses the dosing of moxifloxacin, ofloxacin, and fortified tobramycin/cephazolin for the treatment of bacterial keratitis, but does not provide information on the dosing of Polytrim.

Available Information

• Unfortunately, the provided studies do not contain sufficient information to determine the standard dosing for Polytrim (polymyxin B sulfate and trimethoprim) ophthalmic solution.