Pharmacokinetics of Colistin in Critically-ill Patients With AKI Who Receive SLED

Area under the concentration-time curve [AUC],Maximum Plasma Concentration [Cmax]

Colistin was developed in the 1960s and preliminary pharmacokinetic studies were performed at
 that time. Dosing recommendations, on the basis of these pharmacokinetic studies, are listed
 in the drug's product information. However, there are no optimal dosing recommendations for
 patients with acute kidney injury who receive sustained low-efficiency dialysis. Furthermore,
 the science of antibiotic dosing (pharmacodynamics) has changed significantly since the
 1960s and it is quite possible that the dosing recommendations listed in the product
 information are not optimal. Furthermore, even though physicians refer to colistin
 administration, the only intravenous form of the drug is colistin methanesulfonate (CMS). CMS
 is converted in the body to colistin. Both CMS and colistin have different pharmacokinetic
 and antimicrobial activities. For this reason, we, the investigators at the Mahidol
 university, are performing a pharmacokinetic study of the intravenous CMS/colistin in
 patients requiring sustained low-efficiency dialysis. Plasma concentrations will be
 determined around a CMS/colistin dose once the drug has reached steady state. Microbiologic
 and clinical endpoints will be determined and will be correlated with these concentrations.
 The measurement of CMS and colistin levels will be determined by a laboratory in Australia.