Dose:    20 mg/kg/dose IV (use 40 mg/kg/dose for CNS infections)
               Reduce dose in renal failure.

Frequency: Q 8 hours           

Indications: Meropenem is a broad-spectrum carbapenem antibiotic that is currently used in place of imipenem-cilastatin.   Meropenem is bacteriocidal against Groups A, D and B streptococci; Staphylococcus aureus and epidermidis (though methicillin-resistant organisms may be resistant); E.coli; Proteus species; Citrobacter; Klebsiella; Serratia and Enterobacter species; H. influenza and parainfluenza; Gardnerella vaginalis; P. aeruginosa; Acinetobacter species; Bacteroides species; and Clostridium species. Meropenem is clinically and microbiologically effective as a single agent in most cases of community-acquired infections such as soft tissue, bone, joint, and urinary tract as well as meningitis. It appears to have a comparable safety profile as cefotaxime. There are few situations in which this drug would be used in the NICU. Currently there are no clinical studies of efficacy in neonates. An example of its use would be an older infant who has a gram negative infection resistant to cephalosporins and aminoglycosides but sensitive to meropenem (Bradley. Pediatr Infect Dis J 1997; 16:263). Meropenem has been shown to be efficacious in a number of serious illnesses in infants and children, i.e., those caused by antibiotic-resistant organisms, those caused by multiple aerobic and anaerobic organisms, and those present in the central nervous system. Meropenem appears to have less toxicity in children than imipenem; in animal studies, imipenem was most likely to facilitate seizures in CNS infection while meropenem was least likely (Day. Toxicol Lett 1995; 76:239). Meropenem can also be used to treat polymicrobial infections due to a variety of gram positive and gram negative aerobes and anaerobes. Bacterial resistance is likely to parallel increased use of the drug. Dosage in infants and children were based on pharmacokinetic studies by Blumer (Antimicr Agents and Chemother 1995; 39:1721). Using a dose of 20 mg/kg given every 8 hours will maintain plasma levels above the MIC that inhibits 90% of susceptible bacterial pathogens.

Toxicity: Reported toxicity in adults appears to be low. Local phlebitis (3%) was the most frequent, with pain and erythema at the site of infusion being the next most common problem reported. Systemic reactions reported were diarrhea (5%), vomiting (4%), rash, apnea (1%), and hemorrhages (GI hemorrhages, melena, and epistaxis). The adverse effects reported in infants are similar to adults. Laboratory abnormalities include eosinophilia, thrombocytopenia, thrombocytosis, prolonged PT and PTT, shortened PT and PTT, and increased liver enzymes (Facts and Comparisons, Inc. Drug Facts and Comparisons. Olin, B.R. ed. St. Louis, MO:Facts and Comparisons, Inc; 1997, page 339m).

Preparation: Pharmacy will prepare meropenem (Merrem) in a 50 mg/ml concentration using normal saline which is stable for 18 hours under refrigeration after dilution. If the approximately 1 mEq/kg/day of sodium is excessive, the medication can be diluted in Sterile Water for Injection but has a stability of only 12 hours if refrigerated. Infuse over 3 to 5 minutes.

Compatibility: Compatibility with filter is unknown. Compatible with D5W, D10W, dextrose-saline solutions, dextrose-potassium solutions, LR, normal saline, and sodium bicarbonate. It is also compatible with aminophylline, atenolol, atropine, dexamethasone, digoxin, diphenhdramine, dobutamine, dopamine, enalaprilat, fluconazole, furosemide, gentamicin, heparin, insulin, magnesium sulfate, metoclopramide, morphine, phenobarbital, ranitidine, and vancomycin.. It is incompatible with TPN, amphotericin, diazepam, metronidazole, and multivitamins. It as equivocal compatibility with acyclovir, calcium gluconate, and zidovudine.