Intravenous Labetalol and Intravenous Diazoxide in Severe Hypertension Complicating Pregnancy

Abstract

The results of a prospective trial to evaluate the use of diazoxide and labetalol given intravenously in the management of severe hypertensive disease in pregnancy are presented. Both drugs had an efficient hypotensive action. The reduction in blood pressure in the labetalol group was better controlled and this may be a factor influencing perinatal outcome. Because of the freedom of maternal and fetal side-effects, labetalol given by intravenous infusion is a more appropriate drug for use in the management of hypertensive crises occurring in pregnancy and labour.

Short-term treatment of severe hypertension of pregnancy: prospective comparison of nicardipine and labetalol

“…Indeed success rates between 40% and 93% have been reported [6,28,29]. The highest rate was obtained in a study using a therapeutic success criterion that was different from ours.…”

“…Its immediate and prolonged effect, the increase in uteroplacental flow that occurs with the reduction in uterine vascular resistance [27], and the rarity of maternal and fetal side effects lead to it being frequently used [6,28,29]. Nevertheless, there is wide interpatient variability in the dose of labetalol required to control BP, an event that is not predictable by any clinical item before therapy.…”

“…When fewer doses were used, Holbrook et al [11] observed neither hypoxemia nor acidosis in the ovine fetus. A study designed to evaluate transplacental passage of nicardipine showed that fetal plasma concentrations of nicardipine reached only 6-9% of maternal plasma values [29], and that tissue concentrations were nearly undetectable a few hours after administration, suggesting that nicardipine does not accumulate in the plasma, membranes, or umbilical cord. Clinical studies with intravenous nicardipine in preeclampsia are scarce and often not controlled [13,14].…”

“…Lunell et al [30] observed a significant reduction in BP starting from the 10th min of therapy. Michael [29] and Garden et al [28] used prospective continuous infusion doses (20-160 mg per hour in the first study and 0.5 and 3 mg/kg per hour in the second) and recorded a significant BP reduction as soon as the 5th min of therapy.…”

RETIRED: Diagnosis, Evaluation, and Management of the Hypertensive Disorders of Pregnancy

“…For refractory hypertension in intensive care, higher dose diazoxide can be considered (although there is more hypotension than with labetalol) [339] as can sodium nitroprusside (being mindful of the unproven risk of fetal cyanide toxicity) [340].…”