Table 3.

Oral antihypertensive drugs commonly used in pregnancy

Drug	Indication	FDA category	Initial dose	Maximum dose	Potential side effects
Methyldopa	Often used as first line	B	125-250 mg BD	500 mg QID	Lethargy
Labetalol	Often used as first line	C	100 mg BD	200-400 mg QID	Exacerbation of asthma
Nifedipine (immediate release)	Second line or alternative first line	C	10-20 mg BD	40 mg BD	Concern for synergy with magnesium sulfate for neuromuscular depression

Modified from: Queensland Clinical Guideline: Hypertensive disorders of pregnancy (23) and Chronic Hypertension in Pregnancy (16). Category 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, Category 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, BD; Twice a day, and QID; Four times a day.