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

Treatment of Bacterial Conjunctivitis with Polytrim (Polymyxin B and Trimethoprim)

For bacterial conjunctivitis, Polytrim (polymyxin B and trimethoprim) should be administered as 1 drop in the affected eye(s) every 4 hours for 7-10 days. 1, 2

Indications

• Polytrim is indicated for the treatment of surface ocular bacterial infections including acute bacterial conjunctivitis and blepharoconjunctivitis 1, 2
• Effective against common pathogens including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus viridans, Haemophilus influenzae, and Pseudomonas aeruginosa 1, 2

Dosage and Administration

• Standard dosing: 1 drop in the affected eye(s) every 4 hours (4 times daily) for 7-10 days 3, 4
• Complete the full course of treatment even if symptoms improve before completion 3
• Clinical studies show that 95% of infected eyes treated with Polytrim were cured or improved within 7 days 4

Efficacy Considerations

• Polytrim has demonstrated comparable efficacy to other antibiotics like gentamicin and sodium sulfacetamide in treating bacterial conjunctivitis 5
• At 7-10 days after treatment initiation, clinical cure rates range from 84-95% 5, 4
• However, newer fluoroquinolones like moxifloxacin may provide faster resolution of symptoms (81% resolution at 48 hours with moxifloxacin vs. 44% with Polytrim) 6

Special Populations and Considerations

• Polytrim is particularly useful in pediatric patients with bacterial conjunctivitis 4
• For severe cases or when gonococcal infection is suspected, obtain conjunctival cultures before initiating treatment 3
• Important: Gonococcal and chlamydial conjunctivitis require systemic antibiotic therapy rather than topical treatment alone 7, 3

Follow-up Recommendations

• Patients should be advised to return for follow-up if no improvement is seen after 3-4 days of treatment 7, 3
• At follow-up visits, perform interval history, visual acuity measurement, and slit-lamp biomicroscopy 7

Pitfalls and Caveats

• Bacterial resistance is a growing concern, particularly with MRSA infections 3
• For methicillin-resistant S. aureus (MRSA) infections, alternative treatments like vancomycin may be required 3
• Poor adherence to the frequent administration regimen (every 4 hours) can contribute to treatment failure 3
• If severe inflammation of the conjunctiva or eyelid is present, a brief course of topical corticosteroids may be indicated, but baseline and periodic measurement of intraocular pressure should be performed 7

When to Refer to an Ophthalmologist

• Visual loss 7
• Moderate or severe pain 7
• Severe, purulent discharge 7
• Corneal involvement 7
• Conjunctival scarring 7
• Lack of response to therapy 7
• Recurrent episodes 7