What is the drug of choice for managing gestational hypertension?

Drug of Choice in Gestational Hypertension

Methyldopa is the first-line drug of choice for managing gestational hypertension due to its established safety record and extensive clinical experience. 1, 2

Treatment Algorithm for Gestational Hypertension

Initial Assessment and Thresholds for Treatment

• Non-pharmacological management should be considered first for pregnant women with mild hypertension (SBP 140-149 mmHg or DBP 90-99 mmHg) 1
• Initiate antihypertensive therapy when:
  • BP ≥140/90 mmHg in women with gestational hypertension (with or without proteinuria), pre-existing hypertension with superimposed gestational hypertension, or hypertension with subclinical organ damage 1
  • BP ≥150/95 mmHg in all other pregnant women 1

First-Line Treatment Options

• Methyldopa (750 mg to 4 g per day in 3-4 divided doses) is the preferred first-line agent because:
  • It has the best safety record with no evidence of adverse effects in mothers or babies 1
  • Long-term pediatric follow-up has shown no adverse effects 3
  • It is specifically identified as the drug of choice in pregnancy by multiple guidelines 1, 2

Alternative Treatment Options

• Labetalol (100 mg twice daily up to 2400 mg per day) is an effective alternative with:

  • Efficacy comparable to methyldopa 2
  • Combined alpha and beta-blocking properties providing vasodilation 1, 4
  • No evidence of teratogenicity 4

• Nifedipine (calcium channel blocker) is another option:

  • Particularly effective in achieving blood pressure control within 6 hours 5
  • A recent randomized controlled trial showed nifedipine resulted in better blood pressure control than methyldopa (84% vs 76%) 5
  • Should be used with caution when combined with magnesium sulfate due to risk of hypotension 1

Management of Severe Hypertension (Emergency)

• SBP ≥170 mmHg or DBP ≥110 mmHg requires immediate hospitalization 1
• Treatment options for severe hypertension include:
  • IV labetalol
  • Oral methyldopa
  • Oral nifedipine 1
• IV hydralazine should be avoided due to association with more perinatal adverse effects 1
• For hypertensive crises, sodium nitroprusside (0.25-5.0 mg/kg/min) can be used, but prolonged treatment risks fetal cyanide poisoning 1
• For pre-eclampsia with pulmonary edema, nitroglycerin is the drug of choice 1

Important Considerations and Caveats

• Avoid ACE inhibitors, ARBs, and direct renin inhibitors during pregnancy due to risk of fetopathy 2
• Atenolol should be used with caution due to potential association with fetal growth restriction 1, 2
• Methyldopa should be avoided post-partum due to risk of post-natal depression 1
• A systematic review found that nifedipine may be preferred as first-line agent for severe hypertension with lower risk of persistent hypertension compared to hydralazine and labetalol 6
• Diuretics are controversial in pregnancy and should only be used in combination with other drugs, particularly when vasodilators exacerbate fluid retention 1

Long-term Considerations

• Women who develop gestational hypertension are at increased risk of hypertension and cardiovascular disease later in life 1
• Women experiencing hypertension in their first pregnancy are at increased risk in subsequent pregnancies 1
• Close monitoring is required in the early postpartum period as hypertensive disorders can worsen or initially present after delivery 7