Comparative Pharmacology
Head-to-head clinical analysis: COLISTIMETHATE SODIUM versus COLY MYCIN M.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COLISTIMETHATE SODIUM versus COLY MYCIN M.
COLISTIMETHATE SODIUM vs COLY-MYCIN M
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Colistimethate sodium is a prodrug that hydrolyzes to colistin, a polymyxin antibiotic. Colistin disrupts bacterial cell membrane integrity by binding to lipopolysaccharides and phospholipids, increasing permeability leading to cell death.
Colistin acts as a cationic detergent, binding to and disrupting the bacterial cell membrane, leading to cell death. It is active primarily against gram-negative bacteria.
2.5-5 mg/kg/day IV divided every 8-12 hours, based on colistin base activity (CBA). The typical dose is 2.5-5 mg/kg/day of colistimethate sodium (CMS) administered intravenously in 2-3 divided doses. For critically ill patients, a loading dose of 5 mg/kg CBA (approximately 9 million IU) may be given, followed by maintenance doses adjusted for renal function.
2.5 to 5 mg/kg/day of colistin base activity divided every 8-12 hours intravenously; alternatively, 1.25 to 2.5 mg/kg every 12 hours. For inhalation, 75 mg (1 million units) of colistimethate sodium in 3 mL normal saline nebulized twice daily.
None Documented
None Documented
In adults with normal renal function: 2-3 hours (terminal). Prolonged to 20-40 hours in moderate-severe renal impairment; >40 hours in anuria. Dose adjustment required for CrCl <50 mL/min.
Terminal elimination half-life of colistin (active formed moiety) is approximately 3-4 hours in patients with normal renal function; prolonged to 3-4 days in end-stage renal disease. Half-life of CMS itself is shorter (~2 hours). Clinical context: Dosing adjustments are critical in renal impairment to avoid accumulation and neuro/nephrotoxicity.
Primarily renal (tubular secretion and glomerular filtration); 60-70% of the dose is excreted unchanged in urine within 24 hours, with up to 80% recovered over 48 hours. Minor biliary/fecal elimination (<4%).
Primarily renal (approximately 60-70% of colistin [formed from CMS] excreted unchanged in urine via glomerular filtration and tubular secretion); ~10-20% biliary/fecal as unchanged drug. Colistimethate sodium (CMS) is also renally cleared. In renal impairment, clearance is significantly reduced.
Category C
Category C
Polymyxin Antibiotic
Polymyxin Antibiotic