Acute effect of an antihypertensive drug, labetalol, on uteroplacental blood flow

Abstract

Summary. The effect of a new antihypertensive drug, labetalol, on uteroplacental blood flow was determined in eight pre‐eclamptic women. After injection of 0.5 mCi of 113mIn the radioactivity in the placenta was recorded by a gamma camera linked to a computer and the placental blood‐flow index was calculated from the ratio between the maximum radioactivity of the isotope‐accumulation curve and the rise time of the curve. Labetalol, a combined α‐ and β‐adrenoceptor antagonist was given intravenously and after 30 min a second uteroplacental blood‐flow index was calculated. There was a significant mean decrease of blood pressure from 147/98 to 128/83 mmHg, but no change in uteroplacental blood‐flow index, so that uteroplacental vascular resistance tended to decrease.

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

“…This is consistent with previously published data using labetalol at similar doses as those administered in our study. 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.…”

Inadvertent intrathecal injection of labetalol in a patient undergoing post-partum tubal ligation

“…It is commonly used in obstetrics in the treatment of preeclampsia. [11][12][13][14][15] The formulation for intravenous injection is isotonic with a pH ranging from 3 to 4. Each mL of solution contains 5 mg of labetalol hydrochloride, 45 mg of anhydrous dextrose, 0.1 mg of EDTA, 0.8 mg of methylparaben and 0.1 mg of propylparaben as preservatives.…”

Study of Color Doppler of Uterine Artery, Umbilical Artery, Middle Cerebral Artery in PIH Patients on Antihypertensive Therapy

“…Labetalol was administered via IV route after 30 minutes, a second uteroplacental blood flow index was calculated which showed no change. 8 Similar to…”