Efficacy of nifedipine versus hydralazine in the management of severe hypertension in pregnancy: A randomised controlled trial

Comparing Intravenous Labetalol and Intravenous Hydralazine for Managing Severe Gestational Hypertension

Background Hypertensive disorders of pregnancy are the leading causes of both maternal morbidity and maternal mortality. Hypertensive disorders are acute obstetric emergencies, which refer to various life-threatening medical challenges known to develop during pregnancy, labor, and delivery, requiring urgent attention to reduce blood pressure (BP) for the benefit of the affected mothers and infants. Hydralazine and labetalol have been widely used as the first-line medications in the management of severe hypertension during pregnancy. However, the choice between these two drugs lacks clear evidence regarding their safety and superiority. Several studies have attempted to study intravenous (IV) labetalol versus hydralazine, but very few such comparison studies have been conducted in Africa.  Objective To compare the effectiveness of IV labetalol and IV hydralazine in reducing systolic and diastolic BP in pregnant women with severe hypertension. Also, to determine the time required for hydralazine and labetalol to lower BP to ≤150/100 mmHg, the number of doses needed for each drug, and evaluating maternal and perinatal outcomes. Study design This study employed an open-label randomized clinical trial design conducted in the labor, delivery, and antenatal ward of the Central and Stella Obasanjo Hospital in Benin City. A total of 120 women with severe pregnancy-induced hypertension were randomly assigned to two groups: Group X, consisting of 60 pregnant women, received IV hydralazine at a slow rate of 5 mg for five minutes, repeated every 20 minutes (maximum of five doses) until a blood pressure of ≤150/100 mmHg was achieved. Group Y, also consisting of 60 pregnant women, received IV labetalol in escalating doses of 25, 50, 75, 75, and 75 mg (maximum of 300 mg) every 20 minutes until the blood pressure reached ≤150/100 mmHg. Statistical analysis was performed using SPSS version 23 (IBM Inc., Armonk, New York). Result IV hydralazine achieved the target BP in an average time of 45.80 +/- 25.17 minutes, while IV labetalol took an average of 72.67 +/- 41.80 minutes (p=0.001). The number of doses required to reach the target BP differed significantly between the two drugs. Hydralazine required an average of 1.72 +/- 0.904 doses, whereas labetalol required an average of 3.72 +/- 1.782 doses (p=0.0001). While 45% of women in the hydralazine group attained the target BP with a single dose of hydralazine, only 31.1% of women in the labetalol group were able to attain the target BP with a single dose of labetalol (p=0.02). Overall, target BP was achieved in 55 out of 60 women (91.7%) who were randomized to receive IV hydralazine, whereas 45 out of 60 women (75%) who received IV labetalol achieved the target blood pressure. While hydralazine demonstrated more favorable results in terms of achieving target blood pressure, there were higher incidences of maternal adverse effects in the hydralazine group compared to the labetalol group. However, these adverse effects were not severe enough to warrant discontinuation of the medication. Conclusion IV hydralazine showed faster achievement of the target BP and a lower number of doses required compared to IV labetalol. Additionally, a higher percentage of women in the hydralazine group achieved the target BP with a single dose. However, there were more maternal adverse effects associated with hydralazine, although they were not severe. Perinatal outcomes did not differ significantly between the two groups.

Effectiveness of nifedipine, labetalol, and hydralazine as emergency antihypertension in severe preeclampsia: a randomized control trial

Background: Preeclampsia is a highly prevalent disease among pregnant women. In the event of hypertensive emergency, nifedipine, labetalol, and hydralazine are assigned as first-line therapies in preeclampsia. Further studies are needed to compare the effectiveness of these drugs to find the most cost-effective drug with minimal side effects. This study aimed to compare the effectiveness of these drugs in lowering blood pressure during hypertensive emergencies in severe preeclampsia. Methods: 60 pregnant women with severe preeclampsia were recruited in this multiple centre double-blind randomized clinical trial from May 2021 to April 2022 in Indonesia. The patients were divided equally into three groups and treated with three doses of nifedipine, labetalol, and hydralazine, respectively within one hour with 20 minutes interval. The effectiveness was measured based on systolic and diastolic blood pressures, and mean arterial pressure (MAP). The observation was carried out until five hours post-third dose administration.   Results: The blood pressure was reduced significantly after the administration of the first to the third dose of each antihypertensive (p<0.05). A single dose administration, four, one, and three patients had 20% MAP reduction in nifedipine, labetalol, and hydralazine group. Three, seven, and one patient had a failure of reaching 20% MAP reduction even after receiving the third dose. The effectiveness of the drugs to achieve 20% reduction of MAP could be ranked as follows: nifedipine>labetalol>hydralazine (57.49%, 42.13%, and 40.87%, respectively) for single dose and hydralazine>nifedipine>labetalol (111.3%, 85.12%, and 90.04%, respectively) for triple dose. Conclusions: Nifedipine is the most effective drug to reduce the blood pressure when single dose administration is used, but requires more doses to further reduce the blood pressure. Hydralazine is the most effective when the drug administration is maxed up to three doses within 60 minutes with 20 minutes interval. Thai Clinical Trials Registry (TCTR): TCTR20221014007 (14/10/2022).

Pharmaceutical administration for severe hypertension during pregnancy: Network meta-analysis

Aims: To evaluate the efficacy of different pharmacologic treatment for severe hypertension during pregnancy. Methods: Two reviewers searched Ovid MEDLINE, Ovid EMbase, and the Cochrane Library for randomized clinical trials from the establishment of the database to 15 July 2021 that were eligible for inclusion and analyzed the pharmaceuticals used for severe hypertension in pregnancy. Results: 29 relevant trials with 2,521 participants were involved. Compared with diazoxide in rate of achieving target blood pressure, other pharmaceuticals, including epoprostenol (RR:1.58, 95%CI:1.01-2.47), hydralazine\dihydralazine (RR:1.57, 95%CI:1.07-2.31), ketanserin (RR:1.67, 95%CI:1.09-2.55), labetalol (RR:1.54, 95%CI:1.04-2.28), nifedipine (RR:1.54, 95%CI:1.04-2.29), and urapidil (RR:1.57, 95%CI:1.00-2.47), were statistically significant in the rate of achieving target blood pressure. According to the SUCRA, diazoxide showed the best therapeutic effect, followed by nicardipine, nifedipine, labetalol, and nitroglycerine. The three pharmaceuticals with the worst therapeutic effect were ketanserin, hydralazine, and urapidil. It is worth noting that the high ranking of the top two pharmaceuticals, including diazoxide and nicardipine, comes from extremely low sample sizes. Other outcomes were reported in the main text. Conclusion: This comprehensive network meta-analysis demonstrated that the nifedipine should be recommended as a strategy for blood pressure management in pregnant women with severe hypertension. Moreover, the conventional pharmaceuticals, including labetalol and hydralazine, showed limited efficacy. However, it was important to note that the instability of hydralazine reducing blood pressure and the high benefit of labetalol with high dosages intakes should also be of concern to clinicians.

Comparative efficacy and safety of oral nifedipine with other antihypertensive medications in the management of hypertensive disorders of pregnancy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Hypertensive disorders of pregnancy are the most frequently occurring medical condition during pregnancy, resulting in fetal and/or maternal morbidity and mortality. This meta-analysis compared the efficacy and safety of nifedipine with other antihypertensive medications used in hypertensive disorders of pregnancy.

METHODOLOGY

A comprehensive search was performed using PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar. The meta-analysis was carried out using Review Manager Software, and the pooled effect estimate was generated as standardized mean difference and odds ratio with 95% confidence interval and two-sided P -value.

RESULTS

The meta-analysis was comprised of 22 randomized control trials with 2595 participants. It was found that meantime and number of doses required to achieve target blood pressure were lower in the nifedipine group ( P  < 0.05). Even though it is statistically insignificant, fetal APGAR (Appearance, Pulse, Grimace, Activity, and Respiration) scores less than seven favors nifedipine intervention. Furthermore, none of the fetal or maternal secondary outcomes were found significant.

CONCLUSION

Nifedipine was found to be more effective than other antihypertensive medications to reduce blood pressure, particularly in patients with severe hypertension. However, future clinical studies, including real-world data are necessary to establish the safety profile of nifedipine concerning the fetal outcomes in hypertensive pregnant women.

Antihypertensive Medications for Severe Hypertension in Pregnancy: A Systematic Review and Meta-Analysis

BACKGROUND

Hypertension in pregnancy causes significant maternal and fetal mortality and morbidity. A comprehensive assessment of the effectiveness of antihypertensive drugs for severe hypertension during pregnancy is needed to make informed decisions in clinical practice. This systematic review aimed to assess the efficacy and safety of antihypertensive drugs in severe hypertension during pregnancy.

METHODS

A systematic review using the electronic databases MEDLINE (PubMed) and Cochrane Library was performed until August 2021. The risk-of-bias 2 tool was used to assess the risk-of-bias in each study included. Meta-analysis was conducted to assess heterogeneity and to estimate the pooled effects size.

RESULTS

Seventeen studies fulfilled the inclusion criteria and 11 were included in the meta-analysis. Nifedipine was estimated to have a low risk in persistent hypertension compared to hydralazine (RR 0.40, 95% CI 0.23-0.71) and labetalol (RR 0.71, 95% CI 0.52-0.97). Dihydralazine was associated with a lower risk of persistent hypertension than ketanserin (RR 5.26, 95% CI 2.01-13.76). No difference was found in the risk of maternal hypotension, maternal and fetal outcomes, and adverse effects between antihypertensive drugs, except for dihydralazine, which was associated with more adverse effects than ketanserin.

CONCLUSIONS

Several drugs can be used to treat severe hypertension in pregnancy, including oral/sublingual nifedipine, IV/oral labetalol, oral methyldopa, IV hydralazine, IV dihydralazine, IV ketanserin, IV nicardipine, IV urapidil, and IV diazoxide. In addition, nifedipine may be preferred as the first-line agent. There was no difference in the risk of maternal hypotension, maternal and fetal outcomes, and adverse effects between the drugs, except for adverse effects in IV dihydralazine and IV ketanserin.