Comparative Pharmacology
Head-to-head clinical analysis: OPHTHOCHLOR versus POLYTRIM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: OPHTHOCHLOR versus POLYTRIM.
OPHTHOCHLOR vs POLYTRIM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Chloramphenicol inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing peptide bond formation.
Polymyxin B sulfate binds to the lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria, disrupting membrane integrity and causing cell death. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking the conversion of dihydrofolic acid to tetrahydrofolic acid, thereby inhibiting bacterial DNA synthesis.
Chloramphenicol 0.5% ophthalmic solution: Instill 1-2 drops into the affected eye(s) every 3-4 hours for 7-10 days. For severe infections, every 2 hours initially. Ointment: Apply a small amount (about 0.5 cm) into the conjunctival sac every 3-4 hours.
1 drop in the affected eye(s) every 4 hours for 7-10 days.
None Documented
None Documented
5-6 hours in normal renal function; prolonged up to 24-48 hours in severe renal impairment
Terminal elimination half-life of polymyxin B is 4.5-6 hours; for trimethoprim it is 8-10 hours. In renal impairment, half-life of both components is prolonged.
Renal: 70-80% unchanged; biliary/fecal: 20-30%
Renal excretion accounts for approximately 40% of the dose as unchanged polymyxin B and 60% as unchanged trimethoprim. Biliary/fecal elimination is minimal (<5% for each component).
Category C
Category C
Ophthalmic Antibiotic
Ophthalmic Antibiotic