Comparative Pharmacology
Head-to-head clinical analysis: TERRAMYCIN W POLYMYXIN versus TERRAMYCIN W POLYMYXIN B SULFATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TERRAMYCIN W POLYMYXIN versus TERRAMYCIN W POLYMYXIN B SULFATE.
TERRAMYCIN W/ POLYMYXIN vs TERRAMYCIN W/ POLYMYXIN B SULFATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Terramycin (oxytetracycline) is a bacteriostatic tetracycline antibiotic that inhibits protein synthesis by binding to the 30S ribosomal subunit, preventing aminoacyl-tRNA binding. Polymyxin B is a cationic polypeptide that disrupts bacterial cell membranes by interacting with lipopolysaccharides in Gram-negative bacteria.
Oxytetracycline: inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, blocking aminoacyl-tRNA binding. Polymyxin B sulfate: disrupts bacterial cell membrane permeability by binding to lipopolysaccharides in Gram-negative bacteria.
Not applicable: Terramycin (oxytetracycline) and polymyxin B combination is not available for systemic use; topical or ophthalmic preparations only; no standard adult systemic dose.
1-2 g oxytetracycline (as hydrochloride) plus 100,000-250,000 units polymyxin B sulfate IM every 8-12 hours (deep IM only); ophthalmic: 1-2 drops suspension every 4-6 hours; topical: apply thin layer to affected area 2-4 times daily.
None Documented
None Documented
Oxytetracycline: 6-10 hours (normal renal function; prolonged to 50-100 hours in anuria). Polymyxin B: 6-8 hours (normal renal function; prolonged to 24-48 hours in renal impairment).
Oxytetracycline: terminal elimination half-life is 6-10 hours in patients with normal renal function; extends to 48-60 hours in severe renal impairment. Polymyxin B: terminal half-life is 6-8 hours in normal renal function; prolonged to 2-3 days in anuria.
Renal: Oxytetracycline ~70% unchanged; Polymyxin B ~60% unchanged. Fecal: Oxytetracycline ~20-30% (biliary and unabsorbed); Polymyxin B ~40% (biliary).
Approximately 60% of oxytetracycline is excreted unchanged in the urine via glomerular filtration; 20-30% is eliminated in feces via biliary secretion. Polymyxin B is primarily eliminated by renal tubular secretion, with about 60% of a parenteral dose recovered unchanged in urine within 24 hours; minor fecal elimination.
Category C
Category C
Topical Antibiotic Combination
Topical Antibiotic Combination