What is the recommended dose of Meropenem (generic name) for intravenous administration?

Meropenem Intravenous Dosing

The standard dose of meropenem for adults is 1 gram IV every 8 hours for most serious infections, administered as an infusion over 15-30 minutes, with higher doses (2 grams every 8 hours) reserved for meningitis, severe pneumonia, or infections with resistant organisms. 1

Standard Adult Dosing by Infection Type

Complicated Intra-Abdominal Infections

• 1 gram IV every 8 hours is the recommended dose for complicated intra-abdominal infections 1, 2
• Treatment duration is typically 5-7 days based on source control adequacy and clinical response 2, 3
• This provides excellent anaerobic coverage without requiring additional agents 4

Skin and Soft Tissue Infections

• 500 mg IV every 8 hours for uncomplicated skin and skin structure infections 1
• 1 gram IV every 8 hours when treating infections caused by P. aeruginosa 1
• For necrotizing infections requiring broad-spectrum coverage, use 1 gram IV every 8 hours as part of combination therapy 2

Pneumonia and Respiratory Infections

• 2 grams IV every 8 hours for hospital-acquired or ventilator-associated pneumonia 2
• Extended infusion over 3 hours is recommended for critically ill patients 2, 4
• Treatment duration is at least 7 days 2

Central Nervous System Infections

• 2 grams IV every 8 hours for meningitis caused by Enterobacteriaceae or suspected ESBL organisms 5
• Treatment duration varies by pathogen: 10 days for H. influenzae, 21 days for Enterobacteriaceae or Listeria 2

Administration Methods

Standard Infusion

• Administer over 15-30 minutes for most infections 1
• Doses of 1 gram may also be given as an IV bolus over 3-5 minutes 1

Extended Infusion (Critical for Optimization)

• Administer over 3 hours when treating carbapenem-resistant Enterobacteriaceae (CRE) 2, 4
• Use 3-hour infusion when the pathogen MIC is ≥8 mg/L 2, 4
• Extended infusion is preferred for critically ill patients with healthcare-associated infections 2, 4
• This maximizes the time above MIC, which is the key pharmacodynamic parameter for beta-lactam efficacy 2

Dosing for Resistant Organisms

Carbapenem-Resistant Enterobacteriaceae (CRE)

• 1 gram IV every 8 hours by 3-hour extended infusion as part of combination therapy 2
• For high MIC organisms (≥16 mg/L), increase to 2 grams IV every 8 hours by 3-hour infusion 2
• Combination therapy is mandatory for CRE infections 2

Carbapenem-Resistant Acinetobacter baumannii (CRAB)

• 2 grams IV every 8 hours in combination with colistin for CRAB with meropenem MIC ≤8 mg/L 2
• Extended infusion over 3 hours is recommended 2

Renal Dose Adjustments

Dosage reduction is required when creatinine clearance falls below 50 mL/min: 1

• CrCl 26-50 mL/min: Give recommended dose every 12 hours 1
• CrCl 10-25 mL/min: Give half the recommended dose every 12 hours 1
• CrCl <10 mL/min: Give half the recommended dose every 24 hours 1

Continuous Renal Replacement Therapy (CRRT)

• 1 gram IV every 8 hours is appropriate for most patients on CRRT 6, 7
• Residual diuresis significantly impacts clearance: patients with preserved urine output may require higher doses or extended infusions 7
• CRRT intensity (dialysate flow rate) does not significantly modify clearance 7

Pediatric Dosing

Children ≥3 Months and ≤50 kg

• 10 mg/kg every 8 hours (maximum 500 mg) for skin/soft tissue infections 1
• 20 mg/kg every 8 hours (maximum 1 gram) for intra-abdominal infections 1
• 40 mg/kg every 8 hours (maximum 2 grams) for meningitis 1
• Administer as infusion over 15-30 minutes 1

Children >50 kg

• Use adult dosing: 500 mg every 8 hours for skin infections, 1 gram every 8 hours for intra-abdominal infections, 2 grams every 8 hours for meningitis 1

Infants <3 Months

• Dosing is based on gestational age (GA) and postnatal age (PNA) 1
• Infants <32 weeks GA and PNA <2 weeks: 20 mg/kg every 12 hours 1
• Infants <32 weeks GA and PNA ≥2 weeks: 20 mg/kg every 8 hours 1
• Infants ≥32 weeks GA and PNA <2 weeks: 20 mg/kg every 8 hours 1
• Infants ≥32 weeks GA and PNA ≥2 weeks: 30 mg/kg every 8 hours 1

Critical Pitfalls and Caveats

Coverage Gaps

• Meropenem does NOT cover MRSA or VRE 2, 4
• Add vancomycin or linezolid if MRSA coverage is needed empirically 4
• Do not use meropenem alone for suspected polymicrobial infections involving these organisms 4

Loading Dose

• No loading dose is required for meropenem, unlike colistin or tigecycline 2, 4
• Standard dosing achieves therapeutic levels rapidly 2

Stability Concerns

• Extended 3-hour infusions are stable and recommended 2, 4
• True 24-hour continuous infusions may have stability issues and are not routinely recommended 4

Antimicrobial Stewardship

• Avoid empiric use based solely on HCAP criteria; only use when locally validated risk factors for resistant organisms exist 4
• De-escalate to narrower-spectrum agents when susceptibilities allow 2
• For perioperative prophylaxis in patients colonized with ESBL organisms, ertapenem is preferred over meropenem due to single-dose administration 3

Therapeutic Drug Monitoring

• Consider TDM in critically ill patients, those with altered pharmacokinetics, or when treating organisms with elevated MICs 8
• Target trough concentrations depend on infection severity and pathogen MIC 8