Background Ibuprofen (IBU) is widely used for the prophylactic and therapeutic treatment of patent ductus arteriosus in preterm newborns. The posologic regimen generally used is based on poor data about neonatal pharmacokinetics.

Objective To assess IBU plasmatic concentrations among preterm newborns receiving prophylactic treatment.

Material and Methods IBU plasmatic concentrations have been dosed by means of an HPLC method in 10 neonates with GA <28 wks prophylactically treated with Pedea® (Orphan Europe, iv).

A 1 cc peripheral blood sample has been collected 1 hour after the end of the loading dose infusion (T0) and 24 hours after the 3rd dose (T72). At T72 echocardiography has been carried out to verify the response to the prophylaxis.

Results Ten neonates were included in the study (GA: 26.2±0.6 wks; BW: 805±192 g). At T72 the ductus was found still patent in 5 neonates (50%). Median plasmatic IBU concentrations at T0 and T72 were similar (26.4 vs 26.2 mg/L). No difference was found at T0 in neonates with closed ductus compared to those with open ductus (28.1 vs 27.2 mg/L), whereas higher values, although not statistically significant, were reported at T72 in neonates with closed ductus (38.4 vs 25.2 mg/L).

Conclusions The IBU plasmatic concentrations in our neonates were comparable to those usually considered effective; nevertheless neonates with failed prophylaxis showed lower values at T72. Considering the poor consistency of the sample, if this trend could be confirmed by a larger number of neonates, the posologic regimen should be modified.