24-hour ambulatory blood pressure monitoring: a comparison between transdermal glyceryl-trinitrate and oral nifedipine. Re: glyceryl trinitrate (GTN) patches are unsuitable in hypertensive pregnancy. The efficacy and fetal-maternal cardiovascular effects of transdermal glyceryl trinitrate in the prophylaxis of pre-eclampsia and its complications: a randomized double-blind placebo-controlled trial. [Nitric oxide: its role in the development of pregnancy complications and in their prevention in women with hypertension and chronic glomerulonephritis].
The objective of the present study is to compare the effectiveness of transdermal glyceryl-trinitrate versus oral nifedipine in lowering blood pressure in patients affected by pregnancy-induced hypertension (PIH). Thirty-six consecutive pregnant women have been evaluated at different gestational ages after the diagnosis of PIH or preeclampsia (PE). After a 24-h ambulatory blood pressure monitoring, patients were allocated to three groups: those receiving oral nifedipine and those receiving transdermal glyceryl-trinitrate in a continuous (24 h/day) or intermittent (16 h/day) administration. A second blood pressure monitoring was performed after 2 weeks of treatment. Systolic and diastolic blood pressure were compared by using the Cosinor method looking at mesor, amplitude, and acrophase. Baseline systolic and diastolic blood pressure was similar among the three groups. Neither the transdermal glyceryl-trinitrate administered for 24 or 16 h nor oral nifedipine affected systolic and diastolic blood pressure. Analysis of variance showed that the posttreatment values were similar among the groups. Further studies are needed to verify the possible use of transdermal glyceryl-trinitrate as an antihypertensive drug during pregnancy. nan Pre-eclampsia continues to be a major cause of maternal and perinatal mortality. A disorder of the nitric oxide system is implicated in the pathogenesis of this condition and preliminary studies have suggested a possible therapeutic role for nitric oxide donors in women with established pre-eclampsia. The aim of this study was to determine whether pre-eclampsia and its complications could be prevented by the long-term use of nitric oxide donors in a group of women identified to be at risk on the basis of abnormal uterine artery Doppler measurements.
                We enrolled 40 healthy normotensive women at high risk of pre-eclampsia selected on the basis of abnormal uterine artery Doppler waveforms at 24-26 weeks of gestation. Women were randomly allocated to receive transdermal glyceryl trinitrate 5 mg-patches or equivalent placebo patches in a double-blind randomized study. The primary outcome measures were pre-eclampsia, fetal growth restriction, preterm delivery or small for gestational age/fetal growth restriction rates. Patches were worn daily from recruitment for 10 weeks or until delivery.
                The primary outcomes were not significantly different in the placebo compared to the glyceryl trinitrate group. However, survival analysis of adverse events with gestation in both groups showed a significantly reduced risk of an adverse event in the glyceryl trinitrate group (p = 0.004), equating to a 73% reduction in hazard. There was no difference in maternal systolic and diastolic blood pressure, mean uterine artery resistance index and fetal umbilical and middle cerebral artery pulsatility indices between the groups.
                Low-dose prophylactic transdermal glyceryl trinitrate commenced late in the second trimester did not reduce the incidence of pre-eclampsia, preterm delivery or fetal growth restriction, but may increase the likelihood of a complication-free pregnancy. Transdermal glyceryl trinitrate (5 mg/day) did not affect maternal cardiovascular, uterine artery or fetal arterial Doppler parameters. The activity of NO-synthase and formation of NO (EDRF) were assessed by an increase in the activity of NO-dependent hyanilate cyclase in response to L-arginine in vitro in platelets of 61 pregnant females (39, 8 14 with essential hypertension, preeclampsia and healthy controls, respectively) and in 9 hypertensive nonpregnant females. Compared to healthy pregnant females, EDRF synthesis activity was inhibited in hypertensive gravidas but enhanced in preeclampsia patients. Effectiveness of exogenic donator NO (transdermal nitroglycerine, Nitroderm NNS 5) was studied in a randomised trial of 76 gravidas with essential hypertension (EH), EH and chronic glomerulonephritis (GN). 39 of them were given transdermal nitroglycerine, 37 received acetylsalicilic acid and curantil. The number of treatment failures was the same in both groups. The conclusion is made that nitro compounds are adequate for use in EH and chronic GN gravidas.
There is insufficient evidence to draw reliable conclusions about whether nitric oxide donors and precursors prevent pre-eclampsia or its complications.
[Note: The 13 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]