Resumen de Influencia de la formulación de fenitoína en las concentraciones plasmáticas en un neonato
Carmen López Martín, M. A. Flores, Vicente Faus Felipe
Objective: To describe the kinetic behavior of phenytoin in a newborn with two oral suspension formulations. Method: We collected analytical data, plasmatic concentrations (Pc), and treatment and clinical evolution from the software containing clinical and laboratory records. The compounding was prepared from phenytoin vials. Results: We began intravenous treatment with 20 mg/12 h and Pc = 3.6 µg/ml. We performed sequential therapy with oral phenytoin, compounded at the hospital, waiting to receive Epanutin® (foreign medication). Compounding at 30 mg/8 h produced Pc = 0-1.8 µg/ml with absence of crisis. Once available Epanutin®, it was administered at the same dosage and pattern, obtaining Pc = 40.8 µg/ml, 10 days after. After making dosage adjustments, an 18-24 mg/8 h dose, the patient showed erratic Pc and an irregular response. Conclusions: Compounding did not produce any therapeutic plasmatic levels. The formulation exchange resulted in a severe intoxication. The used compounding interfered in the absorption, affecting the treatment's safety and efficacy
