CEFTRIAXONE - BILIRUBIN - ALBUMIN INTERACTIONS IN THE NEONATE - AN INVIVO STUDY

The in vivo bilirubin-albumin binding interaction of ceftriaxone (CRO) was investigated in 14 non-jaundiced newborns, aged 33-42 weeks of ge station, during the first few days of life after they had reached stab le clinical condition. CRO (50 mg/kg) was infused intravenously over 3 0 min. The competitive binding effect of CRO on the bilirubin-albumin complex was estimated by determining the reserve albumin concentration (RAC) at baseline, at the end of CRO infusion, and at 15 and 60 min t hereafter. Immediately after the end of drug administration, RAC decre ased from 91.9 (+/- 25.1) mumol/l to 38.6 (+/- 10.1) mumol/l (P = 0.00 01). At the same time the plasma bilirubin toxicity index (PBTI) incre ased from 0.64 (+/- 0.40) before drug infusion to 0.96 (+/- 0.44) ther eafter (P = 0.0001). The highest displacement factor (DF) was calculat ed to be 2.8 (+/- 0.6) at the end of drug infusion. Average total seru m bilirubin concentrations decreased from a baseline value of 59.6 (+/ - 27.0) mumol/l to 55.2 (+/- 27.1) mumol/l (P = 0.026). Sixty minutes after the end of CRO infusion, RAC was 58.3 (+/- 21.7) mumol/l, PBTI r egained baseline, but DF was still 1.9 (+/- 0.2). No adverse events we re recorded. Our results demonstrate significant competitive interacti on of CRO with bilirubin-albumin binding in vivo. Thus, cefriaxone sho uld not be given to the neonate at risk of developing bilirubin enceph alopathy.