Pharmacokinetics of antihypertensive drugs in the neonatal period.

A consistent body of evidence indicates that in the preterm and full-term newborn drug disposition is reduced when compared to that of infants, grown-up children, and adults. Newborns are rarely treated directly with antihypertensive agents; however they can be exposed to the action of various antihypertensive drugs in utero and during their first week of extrauterine life in the case of hypertensive mothers treated through pregnancy. In such cases, the persistence of the antihypertensive agent during the first days of life may have important consequences on neonatal haemodynamics and on the function and the maturation of vital organs such as lungs and kidneys. The available information on the placental transfer and neonatal pharmacokinetics of alpha-methyldopa, clonidine, acebutolol, atenolol, betaxolol, metoprolol, propanolol, oxprenolol, and latetalol, are reviewed. Each product has its own pharmacokinetic characteristics which should influence, depending on the clinical situation, the therapeutic choice. In the presence of comparable efficacy, preference should be given to compounds with high bioavailability, eliminated mainly via metabolic degradation, with no active metabolites. In all cases, treatment should be discontinued 8-12 h before delivery.