Antihypertensive Agents in Pregnancy

FOR USE BY MEDICAL PROFESSIONALS. Verify dosing with current labeling and your institution’s OB safety-bundle/order sets. Individualize therapy based on gestational age, diagnosis (chronic HTN vs gestational HTN vs preeclampsia), and comorbidities (asthma, bradycardia/heart block, renal/hepatic disease).

Quick index

Definitions & key thresholds

Severe-range (acute-onset) hypertension Sustained SBP ≥ 160 and/or DBP ≥ 110 mmHg is treated urgently with fast-acting agents to reduce stroke risk while avoiding hypotension [1].
After initial control, many protocols target about 130–150 / 80–100 with close monitoring.
Chronic hypertension — treatment threshold Contemporary guidance supports initiating or titrating therapy for chronic hypertension in pregnancy at approximately BP ≥ 140/90, with individualized targets and follow-up [1].

Chronic blood pressure control (maintenance)

General approach (maintenance)
  • First-line (common) Labetalol and nifedipine ER are frequently used [1].
  • Alternatives Methyldopa and selected beta-blockers (e.g., metoprolol/propranolol) may be used for specific indications or intolerance to first-line agents; oral hydralazine and thiazides are used selectively.
  • Adjunct / selected alternative Clonidine may be used when preferred agents are not suitable/tolerated (monitor for sedation and rebound hypertension if stopped abruptly) [3].
  • Confirm home BP technique, assess symptoms, review medications that raise BP (e.g., NSAIDs postpartum), and plan fetal surveillance per chronic HTN pathway.
“How supplied” should be verified in product labeling (DailyMed) and/or a drug compendium [4][5].

Labetalol (oral) — maintenance

Common first-line Mixed α/β blocker used for chronic HTN control in pregnancy and postpartum [1].

How administered
Initial: 100 mg PO twice daily. Increase by 100 mg PO twice daily every 2–3 days as needed; titration increments should not exceed 200 mg PO twice daily.
Typical maintenance: 200–400 mg PO twice daily; some patients may require 1200–2400 mg/day (divided). Confirm per labeling/protocol [4].
Typical use
Chronic hypertension maintenance; postpartum continuation if needed.

Dose/titration vary; use your institutional pathway and current labeling.

How supplied
Tablets: 100 mg, 200 mg, 300 mg (verify by manufacturer) [4][5].
Package insert / labeling
DailyMed: labetalol (search)  |  FDA Drugs@FDA search
Key cautions
Asthma/bronchospasm Bradycardia/heart block Monitor maternal HR/BP.

Nifedipine extended-release (ER) — maintenance

Common first-line Calcium channel blocker; ER formulation used for chronic BP control [1].

How administered
Initial: 30–60 mg PO once daily. Increase gradually every 7–14 days.
Typical maintenance: 30–90 mg PO once daily.
Maximum: up to 120 mg/day (per labeling/protocol) [4].
Typical use
Chronic hypertension maintenance in pregnancy and postpartum.

Use ER for maintenance. IR nifedipine is typically reserved for acute severe-range treatment in protocols.

How supplied
Tablets: 30 mg, 60 mg, 90 mg (verify by manufacturer) [4][5].
Package insert / labeling
DailyMed: nifedipine ER (search)
Key cautions
Headache/flushing/edema; avoid overshoot hypotension.

Hydralazine (oral) — maintenance (selected patients)

Adjunct / alternative Peripheral vasodilator. Less common for maintenance than labetalol/nifedipine ER; consider when preferred agents are not suitable.

How administered
Initial: 10 mg PO four times daily for 2–4 days → increase to 25 mg PO four times daily for the remainder of week 1 → then 50 mg PO four times daily if needed.
Some patients may require up to 300 mg/day total for effect (confirm per labeling/protocol) [4].
Typical use
Alternative/adjunct maintenance agent.

Dosing is individualized; confirm with your protocol and labeling.

How supplied
Tablets: 10 mg, 25 mg, 50 mg, 100 mg (verify by manufacturer) [4][5].
Package insert / labeling
DailyMed: hydralazine (search)
Key cautions
Tachycardia, headache/flushing; rare drug-induced lupus with longer-term use (label) [4].

Methyldopa — maintenance (alternative)

Alternative Long history in pregnancy; often limited by sedation/tolerability [1].

How administered
Initial: 250 mg PO two to three times daily for the first 48 hours. Adjust at intervals of ≥2 days; to minimize sedation, make dose increases in the evening.
Maintenance: 500 mg–2 g/day in 2–4 doses.
Maximum: 3 g/day (confirm per labeling/protocol) [4].
Typical use
Alternative maintenance agent when first-line agents are not suitable or tolerated.
How supplied
Tablets: 250 mg, 500 mg (verify by manufacturer) [4][5].
Package insert / labeling
DailyMed: methyldopa (search)
Key cautions
Sedation, depression; rare hepatotoxicity/hemolytic anemia (label) [4].

Clonidine — maintenance (selected use / adjunct)

Selected use Central α2-agonist; may be used when preferred agents are not suitable/tolerated. Avoid abrupt discontinuation (rebound HTN) [3].

How administered
Oral tablets (divided dosing; titrate). Transdermal systems exist but are less commonly used in OB pathways (institution-dependent).
Example dosing (adult HTN)
Initial: 0.1 mg PO twice daily (morning and bedtime). Increase by 0.1 mg/day at weekly intervals (or per protocol) to BP response.
Usual maintenance: 0.2–0.6 mg/day in two doses.
Maximum (adult labeling): up to 2.4 mg/day divided (confirm per labeling/protocol) [3][4].

Use the lowest effective dose. If discontinuing, taper to reduce rebound hypertension risk.

How supplied
Tablets: 0.1 mg, 0.2 mg, 0.3 mg (verify by manufacturer) [4][5].
Package insert / labeling
DailyMed: clonidine HCl tablets (search)  |  FDA Drugs@FDA (basic search)
Key cautions
Rebound HTN if stopped abruptly Sedation / dizziness Bradycardia

Monitor maternal HR/BP; counsel about orthostasis. Consider additive sedation with other CNS depressants. If used near delivery, newborn monitoring may be warranted per local protocol.

Metoprolol — maintenance (selected use)

Selected use β1-selective blocker often used for maternal arrhythmias; may be used for BP control when clinically appropriate.

How administered
Immediate-release: Initial 100 mg/day PO (single or divided). Maintenance 100–450 mg/day PO; titrate at weekly (or longer) intervals.
Extended-release: Initial 25–100 mg PO once daily. Maintenance 100–400 mg PO once daily; titrate at weekly (or longer) intervals.
Confirm per labeling/protocol [4].
Typical use
Consider when there is a coexisting indication (e.g., tachyarrhythmia) or intolerance to first-line chronic HTN agents.

Prefer agents with the best obstetric evidence for primary HTN control (commonly labetalol or nifedipine ER). Use local protocol.

How supplied
IR tablets: 25, 50, 100 mg (others exist by manufacturer); ER tablets: 25, 50, 100, 200 mg (verify) [4][5].
Package insert / labeling
DailyMed: metoprolol (search)
Key cautions
Bradycardia/heart block Neonatal effects Possible neonatal bradycardia/hypoglycemia with late pregnancy exposure (class effect—monitor per nursery protocol).

Propranolol — maintenance (selected use)

Selected use Nonselective beta-blocker; more commonly used for migraine/thyrotoxicosis/arrhythmia than primary chronic HTN control in pregnancy.

How administered
Immediate-release: Initial 40 mg PO twice daily;  increase every 3  to 7 days .Maintenance 80 to 240 mg/day PO q 8-12 hours
Maximuim dose 640 mg /day.
Extended-release LA: Initial 80 mg PO once daily; Maintenance 120–160 mg/day PO.
Maximuim dose 640 mg /day
Extended-release XL (bedtime): Initial 80 mg PO at bedtime;  May increase every 2 to 3 week . Maintenance 80–120 mg PO at bedtime.
Maximuim dose 120 mg /day
Confirm per labeling/protocol [4].

XL should be taken consistently either with food or on an empty stomach (label).

Typical use
Consider when there is a compelling indication (thyrotoxicosis symptom control, certain arrhythmias, migraine prophylaxis) and BP benefit is desired.

Because it is nonselective, avoid in reactive airway disease when possible.

How supplied
IR tablets: 10, 20, 40 , 60, 80 mg; ER capsules: 60, 80, 120, 160 mg (verify) [4][5].
Package insert / labeling
DailyMed: propranolol (search)
Key cautions
Asthma/bronchospasm Bradycardia Neonatal effects Potential neonatal bradycardia/hypoglycemia with late pregnancy exposure (class effect—monitor per nursery protocol).

Hydrochlorothiazide — selected patients (continue if indicated)

Selected use Often continued when used pre-pregnancy and clinically appropriate (monitor volume/electrolytes).

How administered
Typical initial adult dose: 25 mg PO daily (single dose). May increase to 50 mg/day (single or divided).

Doses above 50 mg/day are often associated with more hypokalemia (label).

How supplied
Tablets: 25 mg, 50 mg (verify) [4][5].
Package insert / labeling
DailyMed: hydrochlorothiazide (search)
Key cautions
Avoid dehydration; monitor potassium/sodium and renal function as clinically indicated.

Acute severe-range hypertension (pregnancy & postpartum)

Fast-acting first-line options (common safety-bundle pathways) IV labetalol, IV hydralazine, or PO nifedipine immediate-release are commonly used [1][2].

Labetalol (IV) — acute control

First-line option Avoid as first choice with bronchospasm/asthma or marked bradycardia/heart block.

How administered
IV push over ≥2 minutes (per protocol), repeat/titrate to response [1][2].
Example step-dose protocol
  • 20 mg IV → reassess in 10 minutes
  • If still ≥160/110: 40 mg IV (over ≥2 minutes) → reassess in 10 minutes
  • If still ≥160/110: 80 mg IV (over ≥2 minutes) → reassess in 10 minutes
  • If still ≥160/110: Administer hydralazine 10 mg IV over more than 2 minutes→ reassess in 20 minutes
  • If still ≥160/110: Obtain emergency consultation MFM or critical care

Proceed per your institutional pathway and safety-bundle toolkit [1][2].

Labeling
DailyMed: labetalol injection (search)

Hydralazine (IV) — acute control

First-line option Common alternative if β-blockade is undesirable (e.g., asthma/bradycardia) [1][2].

How administered
  • 5–10 mg IV (over ≥2 minutes) → reassess in 20 minutes
  • If still ≥160/110: 10 mg IV (over ≥2 minutes) → reassess in 20 minutes
  • If still ≥160/110: Administer labetalol 20 mg IV over more than 2 minutes . → reassess in 10 minutes
  • If still ≥160/110: Administer labetalol 40 mg IV over more than 2 minutes and obtain emergency consultation with MFM or critical care. 

Proceed per your institutional pathway and safety-bundle toolkit [1][2].

Labeling
DailyMed: hydralazine injection (search)

Nifedipine immediate-release (IR, PO) — acute control

First-line option Useful when IV access is delayed/unavailable. Avoid non-protocol sublingual use [1][2].

How administered
Oral IR capsule/tablet per protocol (do not use sublingual unless explicitly specified by protocol) [2].
Example step-dose protocol
  • 10 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: 20 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: 20 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: Administer labetalol 20 mg IV over more than 2 minutes and obtain emergency consultation with MFM or critical care.→

Proceed per your institutional pathway and safety-bundle toolkit [1][2].

Labeling
DailyMed: nifedipine IR (search)

Agents to avoid in pregnancy (typical)

Avoid Generally avoided in pregnancy due to fetal/newborn risks (confirm with current guidance) [1]:

  • ACE inhibitors (e.g., lisinopril, enalapril)
  • ARBs (e.g., losartan)
  • Direct renin inhibitors (e.g., aliskiren)
  • Mineralocorticoid receptor antagonists (e.g., spironolactone) — generally avoided

Postpartum/breastfeeding choices can differ; use lactation-specific references and local protocols (e.g., LactMed) [6].

Standard OBRx disclaimer THE INFORMATION IN THE OBRx CONTENT IS INTENDED SOLELY FOR USE BY THE MEDICAL PROFESSION. IT IS NOT INTENDED FOR LAY PERSONS. The prescribing physician must be familiar with full product labeling and relevant medical literature prior to use.

UPDATED: 1/1/20256

References (click to expand)

References

  1. ACOG Committee Opinion No. 767 (2019): Emergent therapy for acute-onset, severe hypertension during pregnancy and postpartum (interim update). PDF
  2. Acute Hypertension in Pregnancy and Postpartum Algorithm (perinatal quality collaborative toolkit; step-dosing examples). PDF
  3. Clonidine dosing (adult hypertension; adjust per OB protocol): Drugs.com: clonidine dosage
  4. DailyMed (NLM) for manufacturer labeling/package inserts: DailyMed home
  5. PDR.net for “How Supplied” (product forms/strengths): PDR home
  6. LactMed (NIH) (postpartum/breastfeeding medication reference; example record): Clonidine — LactMed record
  7. Countouris M, et al Hypertension in Pregnancy and Postpartum: Current Standards and Opportunities to Improve Care. Circulation. 2025 Feb 18;151(7):490-507. doi: 10.1161/CIRCULATIONAHA.124.073302. Epub 2025 Feb 17. PMID: 39960983

Note: Beta-blockers (including metoprolol and propranolol) may be used in pregnancy for selected indications; monitor for fetal growth issues and neonatal bradycardia/hypoglycemia risk, particularly with exposure near delivery (class effect). Always verify with current guidance and local protocols.