1 INTRODUCTION
Off-label drug use is defined as prescribing marketed drugs outside of the authorized age, indication, weight, dose, formulation or route of administration.1, 2 Drugs have historically been commonly used off label in pediatric population due to the challenge and difficulty to perform clinical trials considering the ethical concerns1 and the dearth of therapeutic options. Neonates in the neonatal intensive care units (NICUs) are especially prone to off-label drug use.3-8 Furthermore, neonates are particularly vulnerable and frequently premature in body systems such as drug absorption, metabolism, transportation and elimination, resulting in variations in the pharmacokinetic (PK) and pharmacodynamic (PD) properties and efficacy or toxicity of drugs administered to the infants.9 For this reason, off-label drug use in neonates has been associated with higher risk of adverse drug reactions.10 Until recently, there are no consensus guidelines about off-label drug use in global. In China, some expert consensus have been reported and a specific law or regulation for off-label drug use is absent.11 Rates of off-label drug use varied as reported by studies in Chinese NICUs due to different grades of hospitals and definitions of off-label use.12-14 We sought to conduct a retrospective, multicenter study including NICUs from regional, representative and different grade hospitals to describe the recent characteristics of off-label prescribing in Chinese neonates.