From the Guidelines
Meropenem dosing for neonates should be based on gestational and postnatal age, with doses ranging from 20-30 mg/kg/dose given intravenously, and frequency adjusted accordingly, as recommended in the most recent guidelines 1.
Meropenem Dosing Recommendations
The dosing of meropenem in neonates varies based on gestational age and postnatal age.
- For neonates with a gestational age less than 32 weeks:
- Less than 14 days postnatal age: 20 mg/kg/dose IV q12h
- Greater than or equal to 14 days postnatal age: 20 mg/kg/dose IV q8h
- For neonates with a gestational age of 32 weeks or more:
- Less than 14 days postnatal age: 20 mg/kg/dose IV q8h
- Greater than or equal to 14 days postnatal age: 30 mg/kg/dose IV q8h
Administration and Monitoring
Each dose should be infused over 30 minutes. It is crucial to monitor renal function during therapy, as meropenem is primarily eliminated by the kidneys, and dose adjustments may be necessary in cases of renal impairment 1.
Efficacy and Safety
Meropenem is a broad-spectrum carbapenem antibiotic effective against many gram-positive, gram-negative, and anaerobic bacteria, including extended-spectrum beta-lactamase (ESBL) producing organisms. The treatment duration typically ranges from 7-14 days, depending on the infection site and severity.
Key Considerations
Given the potential for renal impairment and the need for precise dosing based on gestational and postnatal age, careful consideration and monitoring are essential when administering meropenem to neonates, as indicated in the guidelines 1.
From the FDA Drug Label
For pediatric patients (with normal renal function) less than 3 months of age, with complicated intra-abdominal infections, the meropenem for injection dose is based on gestational age (GA) and postnatal age (PNA).
Table 3: Recommended Meropenem for Injection Dosage Schedule for Pediatric Patients Less than3 Months of Age with Complicated Intra-abdominal Infections and Normal Renal Function Age Group Dose (mg/kg) Dose Interval Infants less than 32 weeks GA and PNA less than 2 weeks 20 Every 12 hours Infants less than 32 weeks GA and PNA 2 weeks and older 20 Every 8 hours Infants 32 weeks and older GA and PNA less than 2 weeks 20 Every 8 hours Infants 32 weeks and older GA and PNA 2 weeks and older 30 Every 8 hours
The recommended dose of meropenem for neonates is 20-30 mg/kg every 8-12 hours, depending on gestational age and postnatal age, for complicated intra-abdominal infections 2.
From the Research
Meropenem Dosing in Neonates
- The dosage of meropenem for neonates has been studied in several research papers 3, 4, 5, 6, 7.
- A study published in 2007 found that meropenem was administered intravenously at a dosage of 20 mg/kg every 12 hours (every 8 hours in Pseudomonas Aeruginosa infections) in 26 neonates with severe infections 3.
- Another study published in 2008 found that a dosage of 20 mg/kg every 8 hours achieved the desired pharmacodynamic target in 95% of preterm neonates and 91% of term neonates against Pseudomonas aeruginosa 4.
- A randomized controlled trial published in 2017 compared the clinical and microbiologic efficacy and safety of prolonged infusions versus conventional dosing of meropenem in neonates with Gram-negative late-onset sepsis, and found that prolonged infusion of meropenem at a dosing regimen of 20 mg/kg/dose every 8 hours was associated with higher clinical improvement and microbiologic eradication 5.
- A study published in 2011 found that meropenem dosing strategies based on postnatal and gestational age achieved therapeutic drug exposure in almost all infants, with a dosage of 20 to 30 mg/kg every 8 to 12 hours 6.
- A study published in 2009 found that a Monte Carlo simulation using the creatinine clearance and weight distributions for pre-term and full-term populations separately, examining 20- and 40-mg/kg doses, 8- and 12-h dosing intervals, and 0.5-h and 4-h infusion times, produced robust target attainments with an 8-h interval 7.
Key Findings
- Meropenem dosage for neonates: 20 mg/kg every 8-12 hours 3, 4, 5, 6, 7.
- Prolonged infusion of meropenem may be associated with higher clinical improvement and microbiologic eradication 5.
- Meropenem dosing strategies based on postnatal and gestational age can achieve therapeutic drug exposure in almost all infants 6.
- The choice of dose and infusion time should be balanced against potential toxicity 7.