What is the recommended dose of Merrem (Meropenem) for a patient with moderately impaired renal function, specifically a creatinine clearance (Ccl) of 60?

Meropenem Dosing for Creatinine Clearance of 60 mL/min

For a patient with a creatinine clearance of 60 mL/min, administer the full recommended dose of meropenem (500 mg for complicated skin and skin structure infections or 1 gram for intra-abdominal infections) every 8 hours without dose reduction. 1

Dosing Algorithm Based on Renal Function

According to the FDA-approved prescribing information, dose adjustments for meropenem are stratified by creatinine clearance thresholds 1:

For CrCl >50 mL/min (which includes your patient with CrCl 60):

• Complicated skin/skin structure infections: 500 mg IV every 8 hours 1
• Intra-abdominal infections: 1 gram IV every 8 hours 1
• Infections caused by Pseudomonas aeruginosa: 1 gram IV every 8 hours 1
• No dose reduction required 1

For CrCl 26-50 mL/min:

• Administer the recommended dose every 12 hours (instead of every 8 hours) 1

For CrCl 10-25 mL/min:

• Administer one-half the recommended dose every 12 hours 1

For CrCl <10 mL/min:

• Administer one-half the recommended dose every 24 hours 1

Administration Details

• Administer as an intravenous infusion over 15-30 minutes 1
• Alternatively, 1 gram doses may be given as an IV bolus injection over 3-5 minutes 1
• The 500 mg dose should be infused, not given as bolus 1

Important Clinical Considerations

Calculating Creatinine Clearance:

• Use the Cockcroft-Gault equation when only serum creatinine is available 1
• Males: CrCl (mL/min) = [Weight (kg) × (140 - age)] / [72 × serum creatinine (mg/dL)] 1
• Females: 0.85 × above value 1

Risk of Subtherapeutic Levels:

• Patients with CrCl in the 50-79 mL/min range (including your patient at 60) may be at risk for target non-attainment, particularly for pathogens with higher MICs 2
• Augmented renal clearance and mild renal impairment have been identified as risk factors for inadequate meropenem exposure 2
• Standard dosing achieved only 48.4% target attainment for MIC 2 mg/L and 20.6% for MIC 8 mg/L in critically ill patients 2

Hemodialysis Patients:

• There is inadequate information regarding meropenem use in patients on hemodialysis or peritoneal dialysis 1
• Approximately 50% of meropenem is removed by intermittent hemodialysis 3

Common Pitfalls to Avoid

• Do not reduce the dose for CrCl of 60 mL/min—this falls above the 50 mL/min threshold requiring adjustment 1
• Do not confuse the dosing intervals: every 8 hours is maintained for CrCl >50, while every 12 hours is only for CrCl 26-50 1
• Consider therapeutic drug monitoring in critically ill patients or those with fluctuating renal function, as large inter- and intra-patient variability exists 2
• For P. aeruginosa infections, always use 1 gram every 8 hours regardless of whether treating skin/soft tissue or intra-abdominal infections 1