Comparative Pharmacology
Head-to-head clinical analysis: COLY MYCIN M versus COLY MYCIN S.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COLY MYCIN M versus COLY MYCIN S.
COLY-MYCIN M vs COLY-MYCIN S
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Colistin is a polymyxin antibiotic that binds to lipopolysaccharides in the outer membrane of Gram-negative bacteria, disrupting the membrane and causing cell death.
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.
2.5 mg/kg/dose IV every 12 hours for 7-14 days (based on colistin base activity).
None Documented
None Documented
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.
Terminal elimination half-life: 2-4 hours in normal renal function; prolonged in renal impairment (up to 24-48 hours in anuria).
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.
Renal: ~70-80% unchanged via glomerular filtration; biliary/fecal: ~15-20% as active drug and metabolites.
Category C
Category C
Polymyxin Antibiotic
Polymyxin Antibiotic