Management of pregnancy‐induced hypertension with pindolol‐comparative study with methyldopa

Ellenbogen, A.; Oe, Jaschevatzky; Davidson, Ariane; Anderman, S.; Grünstein, S

doi:10.1016/0020-7292(86)90015-9

Cited by 28 publications

(8 citation statements)

References 10 publications

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“…The present results disagree with published clinical reports which have demonstrated that a-methyldopa does not cause any effective fetal involvement [5,7,8], This is probably due to the presence of several circulating hor mones and enzymes during pregnancy, which may control the functioning of the umbilical-placental circulation. Particularly important among these hormones are ste roids which have a marked vasodilating effect [9], In addition, a predominant central effect of a-methyldopa has been demonstrated in both animals and humans, act ing on presynaptic ai-adrenergic receptors and causing a reduction of peripheral sympathetic tonus.…”

Section: Resultscontrasting

confidence: 57%

Action of Alpha-Methyldopa on Human Umbilical Circulation in vitro

et al. 1992

Gynecol Obstet Invest

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To determine the possible effects of Α-methyldopa on the motility of human umbilical artery, a total of 53 arterial segments were perfused with different concentrations of the drug as follows: 38 segments with 125, 250 and 500 ng/ml of the drug, 9 segments with 500 ng/ml Α-methyldopa in combination with 10^––7M yohimbine, and 6 segments with 10^––7M yohimbine alone. Α-Methyldopa had a vasoconstrictor effect at all doses employed, with a clear dose-effect correlation (p < 0.01). The vasoconstrictor effect of 500 ng/ml Α-methyldopa was fully inhibited in the presence of 10^––7M yohimbine. These results suggest that Α₂-adrenergic receptors are present in the umbilical circulation and that Α-methyldopa may play a role in the control of this circulation.

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Section: Resultscontrasting

confidence: 57%

Action of Alpha-Methyldopa on Human Umbilical Circulation in vitro

et al. 1992

Gynecol Obstet Invest

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“…The present demonstration of the vasconstrictive ef fect of a-methyldopa contrasts with the conclusions of other studies which have shown that a-methyldopa does not effectively impair the fetus [6,9,10], This difference may be due to circulatory hormones and enzymes present during pregnancy which may modulate the umbilicoplacental circulation. Particularly important are the steroids, which have a marked vasodilating effect on human umbil ical artery [11].…”

Section: Resultscontrasting

confidence: 56%

In vitro Study of the Effect of Clonidine on Human Umbilical Artery Motility

Franca

Cunha

Castro

et al. 1994

Gynecol Obstet Invest

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The umbilical-placental circulation is of vital importance for fetal survival and has a dominant effect on the cardiorespiratory physiology of the fetus. The mechanisms of regulation of umbilical vessels appear to differ from those regulating other vessels. Both clonidine and Α-methyldopa have been used in the management of hypertensive complications of pregnancy. In contrast to Α-methyldopa, clonidine does not require previous metabolization but acts directly on the receptors. The action of the two drugs on human umbilical artery was studied in vitro. Forty-eight human umbilical artery segments were dissected and perfused as follows: 9 segments with Α-methyldopa, 10 with clonidine, 10 with yohimbine, 9 with Α-methyldopa in combination with yohimbine, and 10 with pure Tyrode’s solution. Α-Methyldopa had a statistically significant vasoconstrictive effect starting at 40 min (p < 0.05) and this effect was blocked by yohimbine (p < 0.05). Clonidine had no vasoconstrictive effect. The present data for clonidine do not confirm the presence of Α₂-adrenergic receptors in the umbilicoplacental circulation which had been indicated by the action of methyldopa.

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“…This medication is typically administered to patients with heart failures, renal failures, and diabetes [2]. Furthermore, it is one of the few antihypertensives indicated in pregnancy-induced hypertension [2,3]. A structural feature of the drug is an amino acid skeleton with a catechol group as found in DOPA, an anti-Parkinsonism medication.…”

Section: Introductionmentioning

confidence: 99%

Degradation of Methyldopa by Banana

Uesawa

Mohri

2010

Pharmaceuticals

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Methyldopa, an antihypertensive, is a very close analogue of DOPA. Drug interaction accompanied by degradation in a banana juice mixture was reported for DOPA. However, the effect of banana on methyldopa has not been reported. Therefore, we have investigated the impact of banana juice on methyldopa. The drug and supernatant of banana pulp were mixed, and the mixture was observed for changes in color, drug concentration, and ultraviolet-visible absorption spectra at 30 °C. The originally clear and colorless mixture started to acquire a yellow coloration after about 30 seconds after the mixing. The color tone increasingly deepened, then blistered solid particles that do not dissolve were observed after 3 hours. Concentration of methyldopa in the mixture decreased by 60% after 5 min, to 0.5% after 30 min of the mixing. From these findings, it was suggested that the drastic alterations were caused by banana polyphenol oxidase that plays a role in the biosynthesis of melanin pigment from levodopa in banana pulp. Because the degradation of methyldopa occurs extremely fast, it was suggested concomitant use of this anti-hypertensive and banana juice consumption should be avoided in clinical practice.

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Management of pregnancy‐induced hypertension with pindolol‐comparative study with methyldopa

Cited by 28 publications

References 10 publications

Action of Alpha-Methyldopa on Human Umbilical Circulation in vitro

Action of Alpha-Methyldopa on Human Umbilical Circulation in vitro

In vitro Study of the Effect of Clonidine on Human Umbilical Artery Motility

Degradation of Methyldopa by Banana

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