What is the treatment regimen for conjunctivitis using Polytrim (polymyxin B and trimethoprim)?

From the Guidelines

Polytrim (polymyxin B-trimethoprim) eye drops are typically prescribed for bacterial conjunctivitis with a regimen of 1 drop in the affected eye(s) every 4 hours for 7-10 days, as this duration is usually effective in resolving the infection 1. For adults and children over 2 months of age, instill one drop in the affected eye(s) four times daily (every 4 hours while awake) until the infection resolves, usually within 7-10 days. Before application, wash hands thoroughly and avoid touching the dropper tip to any surface to prevent contamination. Gently pull down the lower eyelid to create a pocket, look upward, and place the drop into this pocket. Close the eyes for 1-2 minutes after application to allow proper absorption. If using multiple eye medications, wait at least 5 minutes between applications. Polytrim works by combining polymyxin B, which disrupts bacterial cell membranes, with trimethoprim, which inhibits bacterial DNA synthesis, providing broad-spectrum coverage against common conjunctivitis-causing bacteria. Improvement should be seen within 2-3 days, but the full course should be completed even if symptoms resolve earlier to prevent recurrence or antibiotic resistance.

Some key points to consider when treating conjunctivitis with Polytrim include:

• The choice of antibiotic is usually empiric, and a 5- to 7-day course of a broad-spectrum topical antibiotic is usually effective 1.
• There is no clinical evidence suggesting the superiority of any particular antibiotic, so the most convenient or least expensive option can be selected 1.
• Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotic therapy for treating bacterial conjunctivitis and could be considered when access to antibiotics is limited 1.
• The use of topical antibacterial therapy is associated with earlier clinical and microbiological remission compared with placebo in days 2 to 5 of treatment 1.

It's worth noting that the 2024 study 1 provides the most recent and highest quality evidence for the treatment of conjunctivitis, and its findings should be prioritized when making treatment decisions.

From the FDA Drug Label

Polymyxin B sulfate and trimethoprim ophthalmic solution, USP 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, Streptococcusviridans,Haemophilusinfluenzae andPseudomonas aeruginosa. The treatment regimen for conjunctivitis using Polytrim (polymyxin B and trimethoprim) is not explicitly stated in the provided drug label. Key points:

• The drug label indicates the solution is used for the treatment of surface ocular bacterial infections, including acute bacterial conjunctivitis.
• It does not provide a specific treatment regimen, such as dosage or duration of treatment. 2

From the Research

Treatment Regimen for Conjunctivitis using Polytrim (Polymyxin B and Trimethoprim)

• The treatment regimen for conjunctivitis using Polytrim (polymyxin B and trimethoprim) typically involves administering the ophthalmic solution four times a day for 7 days 3, 4.
• In some cases, the treatment regimen may vary, such as administering the ophthalmic ointment four times a day for seven days or three times a day for five days 5.
• The efficacy of Polytrim in treating conjunctivitis has been compared to other antimicrobial agents, such as moxifloxacin, gentamicin sulfate, and sodium sulfacetamide, with varying results 6, 4, 7.
• Studies have shown that Polytrim is effective in treating bacterial conjunctivitis, with clinical response rates ranging from 47% to 95% 3, 4.
• The safety and tolerability of Polytrim have also been evaluated, with reports of mild-to-moderate adverse events and high patient comfort rates 3, 7.

Comparison with Other Antimicrobial Agents

• Polytrim has been compared to moxifloxacin, with results showing that moxifloxacin is more effective and faster in reducing symptoms and disease transmission 7.
• Polytrim has also been compared to gentamicin sulfate and sodium sulfacetamide, with similar clinical response rates and bacteriologic response rates 4.
• A review of four clinical studies comparing Polytrim to chloramphenicol ophthalmic ointment found that both treatments were effective and well tolerated, with no statistically significant differences between them 5.

Clinical Efficacy and Safety

• The clinical efficacy of Polytrim in treating conjunctivitis has been evaluated in several studies, with results showing that it is effective in reducing symptoms and eradicating bacterial pathogens 3, 4, 5.
• The safety and tolerability of Polytrim have also been evaluated, with reports of mild-to-moderate adverse events and high patient comfort rates 3, 7.