Table 14. Commonly used oral antihypertensive drugs in pregnant women.

Name	Mode of action	Dosage	Categories**	Side effects
Methyldopa	Decreasing sympathetic tone of the brain stem	200–500 mg, 2–4 times/day	B	Depression, Extremely sedation, Hypotension
Labetalol	Blocking α- and β-receptors	50–200 mg q12h, max. 600 mg/day	C	Fetal bradycardia, Pruritus
Nifedipine	Inhibiting calcium influx of arteriolar smooth muscle cells	5–20 mg q8h or sustained release preparation 10–20 mg q12h or controlled release preparation 30–60 mg q.d.	C	Hypotension
Hydrochloro-thiazide*	Diuresis and natriuresis	6.25–12.5 mg/day	B	Placenta bloodstream reduction with high dose diuretics

*Diuretics should be avoided in patients with reduced placenta bloodstream (preeclampsia or fetal growth retardation). **Pregnancy Risk Categories: A, Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy; B, Animal reproduction studies have failed to demonstrate a risk to the fetus, and there are no adequate and well-controlled studies in pregnant women; C, Animal reproduction studies have shown an adverse effect on the fetus, and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.