ABSTRACT
Few data are available for ranitidine pharmacokinetics in the first few days of life. Twenty seven newborn infants were treated with intravenous ranitidine because they were vomiting blood, although they had a negative Apt's test. Each infant provided two blood samples at randomly selected times 30-360 minutes after a 2.4 mg/kg intravenous bolus of ranitidine. A single exponential equation for the concentration-time graph was fitted to the mean serum concentrations at different times. From this model the following mean (SD) measurements wer derived: elimination half life, 207.1 (19.1) minutes; total volume of distribution, 1.52 (0.91) l/kg; and total plasma clearance, 5.02 (0.46) ml/kg/min. Assuming that these measurements do not change with different administered doses, regimens can be derived to assist in planning ranitidine treatment in newborn infants.
Subject(s)
Ranitidine/pharmacokinetics , Gastrointestinal Hemorrhage/blood , Gastrointestinal Hemorrhage/drug therapy , Humans , Infant, Newborn , Ranitidine/therapeutic use , Time FactorsSubject(s)
Diving , Immersion , Sports , Adaptation, Physiological , Animals , Apnea/physiopathology , Child , Hemodynamics , Humans , Syncope/physiopathologyABSTRACT
Neonatal prognostic significance of some biometric parameters in a population study of 331 low-birth-weight newborns was investigated. Multiple logistic regression analysis demonstrates that length, head size and weight are the best predictors of neonatal outcome in small for gestational age (SGA) newborns. In the population of SGA newborns biometric parameters more affected by growth failure were thoracic circumference, weight, head circumference and length, in that order. It seems that the best parameters for the sonographic diagnosis of growth failure are the poorest predictors of neonatal outcome. The possible role of ponderal index as an expression of fetal and neonatal well-being is discussed.
