Use of off-label and unlicensed drugs in the neonatal intensive care unit and its association with severity scores.

Objective: To analyze the frequency of unlicensed (UL) and off-label (OL) prescriptions in neonates admitted to the neonatal intensive care unit of a tertiary care hospital and to determine their association with patients' severity.

Methods: Observational cohort study including drugs prescribed during hospitalization of neonates over a 6-week period between July and August 2011. The drugs were classified as UL and OL for dose, frequency, presentation, age group, or indication, according to an electronic list of drugs approved by the Food and Drug Administration. Patients were followed until hospital discharge or 31 days of hospitalization, with daily records of the Neonatal Therapeutic Intervention Scoring System (NTISS).

Results: We identified 318 prescription items for 61 patients (average of five items/patient); there were only 13 patients with appropriate use of medications (21%). A prevalence of 7.5% was identified for UL prescriptions and 27.7% for OL, and the most prevalent OL use was that related to age group - 19.5%. Fifty-seven medications were computed - one patient received 10 UL/OL drugs during hospitalization. The prevalence of OL uses was higher in preterm infants < 35 weeks and in those with higher severity scores (p = 0.00).

Conclusions: The prevalence of neonates exposed to UL/OL drugs during hospitalization was high, especially for those with higher NTISS scores. Although there is general appreciation that neonates, especially preterm infants, have a high rate of drug use, an assessment including different cultures and countries is still needed to prioritize areas for future research in the pharmacotherapy of this vulnerable population.