Comparative Pharmacology
Head-to-head clinical analysis: BACITRACIN ZINC NEOMYCIN SULFATE POLYMYXIN B SULFATE versus BETHKIS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BACITRACIN ZINC NEOMYCIN SULFATE POLYMYXIN B SULFATE versus BETHKIS.
BACITRACIN ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE vs BETHKIS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Bacitracin zinc inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier that transports peptidoglycan precursors. Neomycin sulfate and polymyxin B sulfate are aminoglycoside and polypeptide antibiotics, respectively; neomycin binds to 30S ribosomal subunit and causes misreading of mRNA, while polymyxin B disrupts bacterial cell membrane permeability by interacting with phospholipids.
Tobramycin, an aminoglycoside antibiotic, binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibiting protein synthesis, leading to bacterial cell death.
Apply topically (ointment or cream) to affected area 1-3 times daily. For ophthalmic use, instill 1-2 drops into affected eye(s) every 3-4 hours.
4 IU/kg (1 mg/kg) intramuscularly or subcutaneously once weekly for 4 weeks, then a maintenance dose of 2 IU/kg (0.5 mg/kg) once weekly.
None Documented
None Documented
Neomycin: 2-3 h; polymyxin B: 4.5-6 h; bacitracin: 1.5 h. Combined: effectively ~2-6 h depending on renal function; clinical context: prolonged with renal impairment.
Terminal elimination half-life 2-3 hours in patients with normal renal function; prolonged to 20-40 hours in severe renal impairment (CrCl <30 mL/min).
Neomycin: ~99% renal; polymyxin B: ~60% renal, 40% fecal; bacitracin: mainly renal (over 90%). Combined: renal (predominant), with minor biliary/fecal contribution (polymyxin B).
Primarily renal excretion of unchanged drug via glomerular filtration; ~90% of absorbed dose excreted in urine within 24 hours; biliary/fecal elimination <5%.
Category A/B
Category C
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic