Comparative Pharmacology
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN SULFATE AND POLYMYXIN B SULFATE GRAMICIDIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN SULFATE AND POLYMYXIN B SULFATE GRAMICIDIN.
BETHKIS vs NEOMYCIN SULFATE AND POLYMYXIN B SULFATE GRAMICIDIN
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 antibiotic that binds to the 30S ribosomal subunit, inhibiting bacterial protein synthesis. Polymyxin B is a polypeptide antibiotic that disrupts bacterial cell membrane permeability by interacting with phospholipids. Gramicidin is a polypeptide antibiotic that increases cell membrane permeability by forming ion channels, leading to bacterial cell death.
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.
Instill 2 drops (or appropriate amount) into affected eye(s) every 2-4 hours for 7-10 days. Frequency may be increased to every 1-2 hours in severe infections. Ophthalmic suspension, not for injection.
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 hours (normal renal function); polymyxin B: 6-8 hours; gramicidin: ~10 hours (estimated from topical absorption). Prolonged in renal impairment, especially for 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%.
Renal: ~95% for neomycin (unchanged), minimal for polymyxin B (1-10% unchanged) and gramicidin (<1%). Fecal: 50-60% for polymyxin B (biliary), ~1% for neomycin.
Category C
Category A/B
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic