Comparative Pharmacology
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus U GENCIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus U GENCIN.
NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN vs U-GENCIN
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.
Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibiting bacterial protein synthesis.
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.
1-2 mg/kg IV every 8 hours for 7-10 days, targeting peak serum concentration of 6-10 mcg/mL and trough <2 mcg/mL.
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 patients with normal renal function; may prolong to 20-40 hours in end-stage renal disease
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.
Primarily renal (glomerular filtration) with 40-70% excreted unchanged in urine within 24 hours; minor biliary/fecal (<5%)
Category A/B
Category C
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic