Chemical Properties
White or almost white, hygroscopic powder.
Definition
ChEBI: A mixture where R = H or Me. Colistin in which each of the primary amino groups is converted to the corresponding aminomethanesulfonic acid sodium salt, commonly by the action of formaldehyde followed by sodium bisulfite. A polymyxin antibiotic derivative,
it is used in the treatment of severe infections, particularly of multidrug-resistant Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii.
Brand name
Coly-Mycin (Monarch).
General Description
Two forms of colistins, colistin sulfate and colistin methanesulfonate sodium (Colistin sodium methanesulfonate)(CMS-Na), are commercially available. CMS-Na is administered intravenously, and CMS, the free base of CMS-Na consisting of CMS A and CMS B, is hydrolyzed in vivo to form active colistin A and colistin B6 . Colistin first became available for clinical use in 1959 and has been used worldwide for several decades[5].
Biological Activity
colistin methanesulfonate is an inactive prodrug of colistin (also known as polymyxin e), which is an antibiotic with effect against most gram-negative bacteria, but also causes nephro- and neurotoxicity [1]. colistin is produced by certain strains of the bacteria paenibacillus polymyxa, and belongs to the class of polypeptide antibiotics known as polymyxins.in vitro: studying the time-kill kinetics of colistin methanesulfonate against a type culture of pseudomonas aeruginosa found that 8.0 or 32 mg/l colistin methanesulfonate began killing at approximately 90 or 30 min, and the mean auc0-240 values were 186.3±6.0 and 90.4±4.1, respectively [2]. besides, by investigation among mucoid and nonmucoid strains of pseudomonas aeruginosa isolated from patients with cystic fibrosis, colistin methanesulfonate was found to require a concentration of 16 times the mic to achieve complete killing within 24 h [3].
Pharmacokinetics
Colistin is administered intravenously as the non-active prodrug, colistin methanesulfonate sodium (CMS). Colistin methanesulfonate sodium (Colistin sodium methanesulfonate) is eliminated mainly by renal clearance. If CMS is cleared rapidly by the kidney, less CMS is converted to colistin resulted in low colistin that could lead to ineffective antibacterial therapy. In patients with normal renal function (1–2 MIU of CMS), approximately 30–60% of a dose of CMS is converted to colistin. The renal clearance of CMS is much more efficient than the conversion of CMS to colistin. Therefore, to achieve a targeted concentration of >2 mg/L, patients must receive four to five times the amount of CMS. There was wide variability of colistin Cmax values (0.6–8.7 mg/L) in plasma among single-dose studies receiving 2–3 MIU of CMS in critically ill patients with preserved renal function. Almost none of the ICU patients achieved a colistin concentration of more than 2 mg/L in the Plachouras et al. and Mohamed et al. studies[4].
storage
4°C, protect from light
References
[1] nation r l, li j. colistin in the 21st century.[j]. current opinion in infectious diseases, 2009, 22(6): 535-543.
[2] bergen p j, li j, rayner c r, et al. colistin methanesulfonate is an inactive prodrug of colistin against pseudomonas aeruginosa.[j]. antimicrobial agents and chemotherapy, 2006, 50(6): 1953-1958.
[3] li j, turnidge j d, milne r w, et al. in vitro pharmacodynamic properties of colistin and colistin methanesulfonate against pseudomonas aeruginosaisolates from patients with cystic fibrosis[j]. antimicrobial agents and chemotherapy, 2001, 45(3): 781-785.
