Comparative Pharmacology
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN AND POLYMYXIN B SULFATES AND BACITRACIN ZINC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN AND POLYMYXIN B SULFATES AND BACITRACIN ZINC.
BETHKIS vs NEOMYCIN AND POLYMYXIN B SULFATES AND BACITRACIN ZINC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Tobramycin, an aminoglycoside antibiotic, binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibiting protein synthesis, leading to bacterial cell death.
Neomycin is an aminoglycoside that binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibition of protein synthesis. Polymyxin B is a polypeptide that disrupts bacterial cell membrane permeability by interacting with phospholipids. Bacitracin inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier in peptidoglycan biosynthesis.
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.
Apply thin layer to affected area 2-3 times daily. For ophthalmic use: 1-2 drops in affected eye every 4 hours, or 1/2 inch ribbon of ointment in conjunctival sac 2-3 times daily.
None Documented
None Documented
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: 2-3 h (terminal), prolonged in renal impairment; polymyxin B: 6-7 h (terminal), extended in renal failure; bacitracin: 1.5 h (if absorbed), not clinically relevant due to minimal absorption.
Primarily renal excretion of unchanged drug via glomerular filtration; ~90% of absorbed dose excreted in urine within 24 hours; biliary/fecal elimination <5%.
Renal: ~90% of absorbed neomycin and polymyxin B; bacitracin zinc: minimal systemic absorption, excreted primarily in feces. For neomycin: ~99% fecal after oral; polymyxin B: ~60% renal, rest biliary; bacitracin: nearly 100% renal if absorbed.
Category C
Category A/B
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic