Comparative Pharmacology
Head-to-head clinical analysis: POLYTRIM versus VASOCIDIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: POLYTRIM versus VASOCIDIN.
POLYTRIM vs VASOCIDIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Vasocidin is a combination of sulfacetamide sodium, a sulfonamide antibiotic that inhibits bacterial dihydropteroate synthase, thereby blocking folate synthesis and bacterial growth, and prednisolone sodium phosphate, a corticosteroid that suppresses inflammation by inhibiting phospholipase A2 and subsequent prostaglandin and leukotriene synthesis.
1 drop in the affected eye(s) every 4 hours for 7-10 days.
One drop of the ophthalmic suspension into the conjunctival sac of the affected eye(s) every 4 hours while awake and at bedtime for 7 days; duration may be extended based on clinical response.
None Documented
None Documented
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.
Terminal elimination half-life is 6-8 hours in patients with normal renal function; prolonged in renal impairment.
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).
Renal: 70-80% as unchanged drug; biliary/fecal: 20-30% as metabolites and unchanged drug.
Category C
Category C
Ophthalmic Antibiotic
Ophthalmic Antibiotic/Corticosteroid Combination