Meropenem Use in Pediatric Oncology - Audit on Indication, Appropriateness and Consumption Comparing Patient Derived and Pharmacy Dispensing Data.

ABSTRACT

BACKGROUND: Meropenem is an important second- or third-line antibiotic in pediatric cancer patients with febrile neutropenia (FN). Concise utilization data of meropenem in this setting is limited. It remains unclear how drug dispensing data from the hospital pharmacy correlate with data derived from patients' files. METHODS: Retrospective audit of meropenem-consumption in a University-affiliated pediatric oncology center in days of therapy (DOT)/100 inpatient days. The individual indication for meropenem was critically reviewed. The real consumption (in g/100 inpatient days) was compared with the drug amounts dispensed by the hospital pharmacy (in gram and in defined daily doses (DDD)/100 inpatient days). All patients receiving at least one dose of meropenem from 1st of April 2016 until the 30th of June 2018 were included. RESULT: Of 235 consecutive patients, 45 (19%) received meropenem, comprising 57 FN events. The probability of receiving at least one dose of meropenem was significantly higher in patients with ALL, AML, NHL and certain CNS tumors. Preceding the use of meropenem, only 5% of patients were known to be colonized with multidrug-resistant Gram-negative pathogens. Meropenem was administered as first-line treatment in 26% of all meropenem cycles, in 74% of all FN events with meropenem, Piperacillin-Tazobactam was used for initial treatment. In 5 of 57 FN events (8.8%), initial blood cultures yielded a Gram-negative pathogen. Concerning definite treatment, appropriate alternatives to meropenem with a smaller spectrum of activity would have been available in 4 cases, but a de-escalation was not performed. The median length of therapy in the meropenem group was 6 days, the corresponding median for days of therapy (DOT) was 12 days. This corresponds with combination therapy in 56% of all meropenem treatments, mostly with teicoplanin. On average, drug dispensing data from the hospital pharmacy were 1.53 times higher than real use (relying on patients' data) without a significant correlation. A higher Case-mix Index positively correlated with meropenem-consumption. CONCLUSION: The use of meropenem should become a target of antibiotic stewardship programs in order to restrict its use to certain indications and preserve its outstanding role as second- or third-line antibiotic in this vulnerable population. Irrespective of the metrics used (g or DDD/100 inpatient days), pharmacy dispensing data do not accurately depict real patient-derived data concerning meropenem use in pediatric cancer patients.