Pharmacokinetics of ranitidine in preterm and term neonates with gastroesophageal reflux

Abstract

BackgroundThe aim of this study was to determine the effect of gestational age on pharmacokinetics of ranitidine in newborns with gastroesophageal reflux.MethodsA prospective, descriptive and pharmacokinetic study was carried out in 30 pre-term and 20 full-term babies. 3 mg/kg of ranitidine was administered intravenously to all the babies and at 0.25, 0.5, 1, 2, 4, and 8 h following the administration, samples of blood were drawn to assess ranitidine levels using high performance liquid chromatographic technique.ResultsPharmacokinetics of ranitidine had a bi-exponential behavior with a half-life elimination of (t1/2el) 2.79 h, area under curve (AUC) of 1688 ng/mL, volume of distribution (Vd) of 1.44 L/kg, and clearance (Cl) of 5.9 L/kg/h. The median plasmatic concentration in pre-terms was 1113 ng/mL and 280 ng/mL in full-terms. Vd, t1/2 and Cl presented high values in preterm although the correlation of Cl with glomerular filtration in term newborns was better.ConclusionsPlasma levels of ranitidine depend on the gestational age of the newborns. However, the possible relationship between after-birth age and pharmacokinetics of the neonates as their internal organs get matured without minding their gestational background.

Efeitos de drogas inibidoras da secreção ácida do estômago sobre as respostas hipotensoras do nitrito de sódio

“…A ranitidina é um antagonista do receptor histamínico H2, possui alta seletividade, e rápido início de ação (Brittain et al 1981;Asseff et al 2016). Essa droga leva a supressão da secreção gástrica de ácido pela competição reversível com histamina aos receptores H2 na membrana basolateral das células parietais (Golan 2014 (Lamers 1996;Azizollahi et al 2016;Xu et al 2016) Os achados relacionados ao uso do omeprazol têm grande relevância, especialmente para pacientes com doenças cardiovasculares que utilizam IBPs, por isso é necessário investigar se outras classes de drogas utilizadas para o tratamento de doenças dispépticas podem levar as mesmas consequências.…”