Comparative Pharmacology
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus NEOMYCIN POLYMYXIN B SULFATES BACITRACIN ZINC HYDROCORTISONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN versus NEOMYCIN POLYMYXIN B SULFATES BACITRACIN ZINC HYDROCORTISONE.
NEOMYCIN AND POLYMYXIN B SULFATES AND GRAMICIDIN vs NEOMYCIN & POLYMYXIN B SULFATES & BACITRACIN ZINC & HYDROCORTISONE
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.
Neomycin, polymyxin B, and bacitracin are antibiotics that inhibit bacterial protein synthesis, disrupt cell membrane integrity, and interfere with cell wall synthesis, respectively. Hydrocortisone is a corticosteroid that suppresses inflammation by inhibiting phospholipase A2, reducing prostaglandin and leukotriene 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.
Apply to affected area 3-4 times daily. Not for use in eyes.
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.
Neomycin: 2-3h (normal renal); polymyxin B: 4-6h (normal renal), prolonged to 2-3 days in renal impairment; bacitracin: ~1.5h after IM; hydrocortisone: 1.5-2h (plasma). Topical: systemic levels negligible.
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.
Neomycin: >90% renal (unchanged) after parenteral; polymyxin B: ~60% renal (unchanged) over 72h; bacitracin: >90% renal (unchanged) after IM; hydrocortisone: hepatic metabolism, metabolites renally eliminated (<1% unchanged). Topical: negligible systemic absorption across intact skin (except bacitracin may be minimally absorbed).
Category A/B
Category A/B
Aminoglycoside Antibiotic
Aminoglycoside Antibiotic