Pharmacoepidemiology of Furosemide in the Neonatal Intensive Care Unit

Furosemide is commonly used off-label in the neonatal intensive care unit (NICU), but current dosing practices vary widely.

To describe dosing practices including route, dose, and duration of exposure to furosemide in a large number of community and tertiary NICUs across North America.

Using the Pediatrix Medical Group Clinical Data Warehouse, we identified infants who received ≥1 dose of furosemide between 1997 and 2016. We excluded infants with incomplete dosing data. We calculated average daily furosemide dose, cumulative dose, total days of exposure, and maximum daily dose. We compared dosing between infants born at <32 weeks gestational age (GA) and ≥32 weeks GA.

A total of 18,572 infants had complete dosing data. The median (interquartile value) postnatal age at first exposure was 11 days (4, 26), the median maximum daily dose was 1.0 mg/kg (0.97, 1.6), the median average daily dose was 1.0 mg/kg (0.88, 1.1), and the median cumulative dose was 2.0 mg/kg (1.0, 4.5). The median total duration of exposure was 2 days (1, 4). A total of 177 (1%) infants received ≥4 mg/kg/day of furosemide. Infants born <32 weeks GA were an older age at initial furosemide exposure compared to those born ≥32 weeks GA: 19 versus 4 days, p < 0.001.

Most infants received short courses of furosemide within the labeled dosing parameters. Further studies are needed to assess the safety and efficacy of furosemide in the NICU.