Polymyxin B Dosing in Severe Renal Impairment

Key Dosing Principles

The standard dose of polymyxin B is 1.5-3 mg/kg/day in 2 divided doses with a loading dose of 2-2.5 mg/kg, and does not require dose reduction for renal dysfunction, as recommended by the Intensive Care Society 1, 2, 3
Polymyxin B does not require dose adjustment for renal impairment because its plasma concentration is not influenced by renal function, unlike colistin, according to the Intensive Care Society 1, 2, 3

Administer 2-2.5 mg/kg as a loading dose to achieve optimal plasma levels on the first day, as recommended by the Intensive Care Society 1, 2, 3
The loading dose should be given to all patients, including those with renal dysfunction, as recommended by the Intensive Care Society 1, 4
The maintenance dose is 1.5-3 mg/kg/day divided into 2 doses, as recommended by the Intensive Care Society 1, 2, 3

Polymyxin B clearance is calculated based on body weight, and renal function does not significantly affect its pharmacokinetics, as confirmed by the Intensive Care Society 1, 2, 3

If the patient requires continuous renal replacement therapy (CRRT), dose adjustment is not necessary, and the standard dose of 1.5-3 mg/kg/day should be used, as recommended by the Intensive Care Society 1, 2, 3

Polymyxin B has a lower incidence of nephrotoxicity compared to colistin, making it a preferable choice in patients with existing renal dysfunction, as recommended by the Intensive Care Society 1, 2, 3

For a 70 kg patient, the loading dose is 140-175 mg, and the maintenance dose is 105-210 mg/day divided into 2 doses, with no reduction needed despite severe renal impairment, as recommended by the Intensive Care Society 1

The standard dosing regimen for polymyxin B should be maintained regardless of creatinine clearance, with a loading dose of 2-2.5 mg/kg and a maintenance dose of 1.5-3 mg/kg/day divided into 2 doses, as recommended by the Intensive Care Medicine guidelines 5
The American College of Critical Care Medicine recommends administering a loading dose of 2-2.5 mg/kg to all patients, including those with severe renal dysfunction, to rapidly achieve therapeutic plasma concentrations 5

The Infectious Diseases Society of America recommends avoiding concurrent nephrotoxic agents, such as aminoglycosides, NSAIDs, diuretics, ACE inhibitors/ARBs, to minimize the risk of nephrotoxicity 6
Therapeutic drug monitoring is encouraged to optimize dosing and minimize toxicity, with a target steady-state average concentration of approximately 3.35 mg/L, as suggested by the Journal of Microbiology, Immunology and Infection guidelines 6