Comparative Pharmacology
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN AND POLYMYXIN B SULFATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BETHKIS versus NEOMYCIN AND POLYMYXIN B SULFATE.
BETHKIS vs NEOMYCIN AND POLYMYXIN B SULFATE
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, causing misreading of mRNA and inhibiting protein synthesis. Polymyxin B sulfate is a cationic detergent that disrupts bacterial cell membrane permeability by interacting with phospholipids, leading to 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.
For irrigation of urinary bladder: 1 mL of solution containing 40 mg neomycin and 200,000 units polymyxin B per mL diluted in 1 liter of 0.9% sodium chloride, instilled via continuous irrigation at a rate of 1 liter per 24 hours. For topical use: apply thin layer to affected area 2-4 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 hours (normal renal function), prolonged to 24-48 hours in renal impairment; Polymyxin B: 4.5-6 hours (normal renal function), extended significantly in renal failure.
Primarily renal excretion of unchanged drug via glomerular filtration; ~90% of absorbed dose excreted in urine within 24 hours; biliary/fecal elimination <5%.
Renal: ~90-95% (neomycin, polymyxin B) unchanged; fecal: 5-10% (biliary excretion negligible).
Category C
Category A/B
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic