Comparative Pharmacology
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus NETROMYCIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus NETROMYCIN.
NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN vs NETROMYCIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Neomycin and gramicidin are aminoglycoside and polypeptide antibiotics, respectively, that inhibit bacterial protein synthesis by binding to the 30S and 50S ribosomal subunits, while polymyxin B is a cationic detergent that disrupts bacterial cell membrane integrity by binding to lipopolysaccharides.
Netromycin is an aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibition of protein synthesis in bacteria.
1-2 drops or a small amount applied to affected eye(s) every 4 hours, or more frequently if severe, for up to 7-10 days. Ophthalmic ointment: apply a 1/2-inch ribbon into conjunctival sac every 3-4 hours.
4-6 mg/kg IV once daily for serious infections; 1.5-2 mg/kg IV every 8 hours for gram-negative infections. Administered as intravenous infusion over 30-60 minutes.
None Documented
None Documented
Neomycin: plasma half-life ~2-3 hours in patients with normal renal function, but can extend to 12-24 hours or more in renal impairment. Polymyxin B: half-life ~6 hours in normal renal function, prolonged significantly in renal failure (up to 2-3 days). Gramicidin: not systemically absorbed; half-life not applicable.
Terminal elimination half-life is 2-3 hours in adults with normal renal function, but may extend to 24-48 hours in patients with impaired renal function.
Neomycin and polymyxin B sulfates and gramicidin are poorly absorbed from intact skin or ophthalmic sites. After topical application, absorbed neomycin is excreted primarily unchanged in urine (30-50% of absorbed dose) via glomerular filtration; polymyxin B is excreted slowly via renal tubular secretion and glomerular filtration (60-70% of absorbed dose in urine); fecal elimination accounts for minor amounts. Gramicidin is not significantly absorbed.
Renal excretion of unchanged drug accounts for 80-90% of elimination via glomerular filtration; biliary/fecal elimination is minimal (<5%).
Category A/B
Category C
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic