Table II.

 Drugs for Chronic Hypertension in Pregnancy

Drug (Food and Drug Administration Risk)a	Dose	Concerns or Comments
Methyldopa (B)	0.5–3.0 g/d in 2 divided doses	Drug of choice according to NHBEP working group; safety after first trimester well documented, including 7‐year follow‐up evaluation of offspring
Labetalol (C)b	200–1200 mg/d in 2 or 3 divided doses	Gaining in popularity as concerns relating to growth restriction and neonatal bradycardia do not seem to have materialized
Nifedipine (C)	30–120 mg/d of a slow‐release preparation	May inhibit labor and have synergistic interaction with magnesium sulfate; small experience with other calcium‐entry blockers
Hydralazine (C)	50–300 mg/d in 2–4 divided doses	Few controlled trials, long experience with few adverse events documented, useful only in combination with sympatholytic agent; may cause neonatal thrombocytopenia
β‐Receptor blockers (C)	Depends on specific agent 25 mg/d	May cause fetal bradycardia and decrease uteroplacental blood flow, this effect may be less for agents with partial agonist activity; may impair fetal response to hypoxic stress; risk for growth retardation when started in first or second trimester (atenolol)
Hydrochlorothiazide (C)		Majority of controlled studies in normotensive pregnant women rather than hypertensive patients, can cause volume depletion and electrolyte disorders; may be useful in combination with methyldopa and vasodilator to mitigate compensatory fluid retention
Contraindicated ACE inhibitors and angiotensin II type 1 receptor antagonists (D)c		Use associated with major anomalies plus fetopathy, oligohydramnios, growth restriction, and neonatal anuric renal failure, which may be fatal

Note: No antihypertensive drug has been proven safe for use during the first trimester of pregnancy. Drug therapy is indicated for uncomplicated chronic hypertension when diastolic blood pressure is −100 mm Hg (Korotkoff V). Treatment at lower levels may be indicated for patients with diabetes mellitus, renal disease, or target organ damage. Abbreviations: ACE, angiotensin‐converting enzyme; NHBEP, National High Blood Pressure Education Program. ^aUS Food and Drug Administration classification. ^bWe omitted some agents (eg, clonidine, α‐blockers) because of limited data on use for chronic hypertension in pregnancy. ^cWe would classify in category X during second and third trimesters. Reprinted with permission from Lindheimer et al. ¹⁴