What is the dose of colistin for impaired renal function with septic shock on inotrope?

From the Guidelines

The recommended dose of colistin for impaired renal function with septic shock on inotrope is a loading dose of 9 MU (5 mg/kg) followed by a maintenance dose of 4.5 MU (2.5 mg) twice daily, with close monitoring of renal function.

Important Considerations

• The maintenance dose should be individually adjusted according to creatinine clearance 1.
• For patients undergoing continuous renal replacement therapy, a dose of at least 9 million IU/day is suggested 1.
• For patients on intermittent hemodialysis, 2 million IU CMS every 12 h is recommended with a normal loading dose 1.
• Renal function should be closely monitored during colistin treatment, as acute kidney injury is a significant factor related to clinical failure and mortality 1.
• The use of colistin-based combination therapy is controversial, but it may be considered in combination with one or more additional agents to which the pathogen displays in vitro susceptibility 1.

Dosing Details

• A loading dose of 9 MU (5 mg/kg) of colistin is recommended, followed by a maintenance dose of 4.5 MU (2.5 mg) twice daily 1.
• The dose should be adjusted based on creatinine clearance, with a suggested maintenance dose of 4.5 MU (2.5 mg) (1.5 CrCl + 30) twice daily 1.
• Polymyxin B may be a suitable alternative to colistin, with a recommended dose of 1.5–3 mg/kg/day and a loading dose of 2–2.5 mg/kg 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION ... The daily dose and frequency should be reduced for the patients with renal impairment Suggested modifications of dosage schedule for patients with renal impairment are presented in Table 1. TABLE 1 Suggested Modification of Dosage Schedules of Colistimethate for Injection, USP for Adults with Impaired Renal Function Degree of Renal Impairment Normal Mild Moderate Severe Creatinine Clearance (mL/min) ≥80 50-79 30-49 10-29 Dosage Schedule 2.5 to 5 mg/kg, divided into 2 to 4 doses per day 2.5 to 3.8 mg/kg, divided into 2 doses per day 2.5 mg/kg, once daily or divided into 2 doses per day 1.5 mg/kg every 36 hours In the presence of impaired renal function, reduce the infusion rate depending on the degree of renal impairment.

The dose of colistin for impaired renal function is as follows:

• Mild impairment: 2.5 to 3.8 mg/kg, divided into 2 doses per day
• Moderate impairment: 2.5 mg/kg, once daily or divided into 2 doses per day
• Severe impairment: 1.5 mg/kg every 36 hours There is no specific dose adjustment mentioned for patients with septic shock on inotrope, so the dose should be based on the degree of renal impairment only 2.

From the Research

Dosing of Colistin for Impaired Renal Function with Septic Shock on Inotrope

• The dosing of colistin in patients with impaired renal function and septic shock on inotrope is a critical consideration due to the risk of nephrotoxicity 3.
• A study published in the Indian Journal of Nephrology found that age, baseline kidney function, and requirement of vasopressor support for treatment of septic shock were significant risk factors for nephrotoxicity in patients treated with colistin 3.
• Another study published in the Journal of Infection in Developing Countries found that a loading dose and maintenance dose of colistin can be effective in treating multidrug-resistant Gram-negative infections, but the risk of nephrotoxicity is still present 4.
• The optimal dosing strategy for colistin in critically ill patients with impaired renal function is not well established, but a dosing algorithm has been developed to achieve desired plasma colistin concentrations, including necessary dose adjustments for patients with impaired kidney function and those on renal replacement therapy 5.
• A study published in the Indian Journal of Critical Care Medicine found that high-dose, extended-interval colistin can be given to critically ill patients without significant risk of nephrotoxicity, but the dosing schedule was adjusted according to body weight and renal function 6.
• The use of colistin in patients with impaired renal function requires careful monitoring of renal function and adjustment of the dose as needed to minimize the risk of nephrotoxicity 7, 3.