Oral nifedipine retard effective for rapid BP control in hypertensive emergencies of pregnancy: Study
About one in ten pregnant women are affected by a common medical disorder called hypertension. Examples of hypertensive diseases during pregnancy include gestational hypertension, pre-eclampsia, eclampsia, and pre-existing hypertension, with or without superimposed pre-eclampsia. One of the biggest causes of mother and neonatal deaths globally is still HDP. There are increased worsened perinatal outcomes disclosed because of severe hypertension. Severe pregnancy-induced hypertension occurs when the systolic blood pressure (SBP) is 160 mmHg or higher and the diastolic blood pressure (DBP) is 110 mmHg or higher.
Preeclampsia can be diagnosed even without proteinuria if the patients are found to have multiorgan damage. Because of the potential of a stroke, intracerebral bleeding, hypertensive encephalopathy, and other end-organ damage, severe PIH needs to be treated right away. Furthermore, there is a higher chance of complications for the developing fetus, such as low birth weight, premature birth, hospitalisation ofneonates in the ICU and surprisingly inappropriate death. Also, it can lead to the risk of developing hypertension and dyslipidemia in early adulthood. Starting the treatment for hypertension reduces the chance of hypertensive crisis and the risk of death of neonates.
Labetalol works by blocking beta-1 receptors in the heart and alpha-1 receptors in blood vessels. This action leads to a dose-related decrease in blood pressure while maintaining a relatively stable heart rate. When administered intravenously, Labetalol takes effect within 5 minutes, with peak effects observed between 10 to 15 minutes. The duration of action is observed to range from 45 minutes to a maximum of 6 hours, offering a scope of effectiveness. Nifedipine, a calcium channel blocker of the dihydropyridine subclass, is money-saving for labourers. It is a hasty and prolonged action and can be ingested orally. However, it is expected to generate an unexpected reduction of blood pressure in the mother and severe pain in the fetus induced by placental hypoperfusion and palpitations that may occur if magnesium sulphate is administered simultaneously. Hydralazine dilates the blood vessels effectively and is the standard therapy for the management of severe PIH complicating pregnancy. Currently, it is an alternative drug to Nifedipine and Labetalol for treating severe pregnancy induced hypertension (PIH) due to its inconsistent effectiveness and adverse effects on the fetus. This research aimed to compare the safety and efficacy of intravenous Labetalol versus oral Nifedipine retard in managing hypertensive emergencies during pregnancy.
A randomized study with 104 pregnant women who had a blood pressure of 160/110 mm Hg or higher compared the effects of Nifedipine (20 mg every 30 minutes, up to five doses) and Labetalol (20 mg, 40 mg, or 80 mg every 15 minutes) until a target blood pressure of 150/100 mm Hg or lower was reached. The main focus was on the time and dosage needed to achieve this goal.
The mean time to achieve target blood pressure was significantly shorter with IV Labetalol (33.85 ± 11.87 minutes) compared to oral Nifedipine (48.56 ± 17.36 minutes; P < 0.0001). The average dose required was lower for Nifedipine (1.73 ± 0.63 mg) than for Labetalol (2.06 ± 0.67 mg; P < 0.01). The total dose needed was higher for Labetalol (70.00 ± 42.57 mg) compared to Nifedipine (33.71 ± 13.14 mg).
The study findings revealed no statistically significant difference between the two groups concerning their general characteristics, including age, parity, gestational age, proteinuria, oedema, mode of delivery, fetal outcomes, and birth weight.
This study was done so that a positive step can be taken toward finding out whether oral tablets are equally efficacious in reducing blood pressure compared with IV as they are simple, flat, and cheaper for poor people. The present study findings show that an intravenous labetalol regimen is the most effective method for rapidly reducing blood pressure during hypertensive emergencies, such as severe preeclampsia. Although IV labetalol effectively maintains lower blood pressure in a short time, oral nifedipine retard is also effective and very well-tolerated for rapid control of blood pressure in hypertensive emergencies, with minimal side effects reported in the present study.
Source: Sudeepthi et al. / Indian Journal of Obstetrics and Gynecology Research 2025;12(3):511–515
