What are the preferred medications for managing hypertension in pregnancy?

From the Guidelines

Labetalol, methyldopa, and nifedipine are the preferred medications for managing hypertension during pregnancy.

Key Considerations

• These medications have established safety profiles in pregnancy and effectively lower blood pressure without compromising uteroplacental blood flow 1.
• Treatment should begin when blood pressure consistently exceeds 150/100 mmHg, with a goal of maintaining blood pressure below 140/90 mmHg.
• Regular monitoring is essential, including home blood pressure measurements and frequent prenatal visits.
• ACE inhibitors, ARBs, and direct renin inhibitors must be avoided during pregnancy as they can cause fetal harm 1.
• Beta-blockers other than labetalol (particularly atenolol) should generally be avoided due to potential fetal growth restriction.

Medication Dosage

• Labetalol is typically started at 100-200 mg orally twice daily, with a maximum dose of 2400 mg/day.
• Methyldopa begins at 250 mg orally twice daily, increasing gradually to a maximum of 3 g/day.
• Extended-release nifedipine is usually prescribed at 30-60 mg daily, with a maximum of 120 mg/day.

Postpartum Care

• Treatment should continue postpartum, with medication adjustments as needed since some antihypertensives can enter breast milk.
• The choice of medication should be based on the individual patient's needs and medical history, with consideration of the potential risks and benefits of each medication 1.

Summary of Recommendations

• First-line antihypertensive medications during pregnancy include extended-release nifedipine and labetalol 1.
• Methyldopa is another consideration for first-line therapy for hypertension in pregnancy, and is the only medication with long-term information on infant outcomes 1.

From the FDA Drug Label

Pregnancy Teratogenic Effects. Reproduction studies performed with methyldopa at oral doses up to 1000 mg/kg in mice, 200 mg/kg in rabbits and 100 mg/kg in rats revealed no evidence of harm to the fetus. There are, however, no adequate and well-controlled studies in pregnant women in the first trimester of pregnancy. Because animal reproduction studies are not always predictive of human response, methyldopa should be used during pregnancy only if clearly needed Published reports of the use of methyldopa during all trimesters indicate that if this drug is used during pregnancy the possibility of fetal harm appears remote.

The preferred medication for managing hypertension in pregnancy is methyldopa.

• Methyldopa has been shown to have a low risk of fetal harm and is often used as a first-line treatment for hypertension in pregnant women 2.
• It is essential to note that while methyldopa is considered safe, it should only be used during pregnancy if clearly needed, and under the guidance of a healthcare provider.
• Labetalol is also used in pregnancy, but the FDA drug label indicates that it should be used only if the potential benefit justifies the potential risk to the fetus 3.

From the Research

Preferred Blood Pressure Medications for Pregnancy

The following medications are commonly used to manage hypertension in pregnancy:

• Methyldopa: a widely used medication for treating hypertension in pregnancy, with a long history of safe use 4
• Labetalol: often recommended for severe hypertension in pregnancy, with studies showing its efficacy and safety 5, 6, 7
• Nifedipine: a viable option for treating severe hypertension in pregnancy, particularly in low-resource settings 5, 6

Comparison of Medications

Studies have compared the efficacy and safety of these medications:

• A randomized controlled trial found that nifedipine retard resulted in a greater frequency of primary outcome attainment than labetalol or methyldopa 5
• A review of guideline recommendations found that oral α-methyldopa and parenteral labetalol are generally considered the drugs of choice for nonsevere and severe hypertension in pregnancy, respectively 6
• A systematic review of pharmacokinetics found that methyldopa, labetalol, and nifedipine have been perceived as safe to use during pregnancy, but further studies are needed to determine optimal dosing and blood pressure targeting 8

Safety and Efficacy

The safety and efficacy of these medications have been evaluated in various studies:

• Methyldopa has been shown to be effective in reducing blood pressure and preventing severe hypertension, with minimal side effects 4
• Labetalol has been found to be quicker and more efficient at controlling blood pressure, with fewer side effects compared to methyldopa 7
• Nifedipine has been shown to be a viable option for treating severe hypertension in pregnancy, with a low risk of adverse outcomes 5