 OBJECTIVE Recently, population PKPD modeling and simulation studies have enabled the development of evidence--based individualized dosing schemes for children with a limited number of subjects, thus improving drug safety and efficacy. The application of PKPD modeling in the most critically ill population of premature infants, with the highest variability in the pharmacokinetics of drugs, and the greatest lack of adequate data underscoring optimal dosage, can contribute to the development of rational, individualized and safe dosing regimens. 