Table 5.
Antihypertensive drugs used in pregnancy and lactation
| Atenolol | Captopril | Enalapril | Labetalol | Methyldopa | Hydralazine | Nifedipine | |
|---|---|---|---|---|---|---|---|
| Mechanism | Beta blocker | ACE inhibitor | ACE inhibitor | Beta blocker | Alpha 2 agonist | Vasodilator | Calcium channel blocker |
| Pregnancy | Avoid in first and second trimester. Associated with fetal growth restriction and bradycardia, reduces uteroplacental blood flow | No – associated with severe fetal anomaly, fetal nephropathy, and intrauterine death | No – associated with severe fetal anomaly, fetal nephropathy, and intrauterine death | Yes. Can be given intravenously for rapid control of severe resistant hypertension | Yes, including first trimester. Longest post-marketing surveillance data | Used intravenously for rapid blood pressure control. May be associated with neonatal thrombocytopenia. Long history of use. Avoid rapid intravenous bolus because of risk of hypotension | After 20 weeks. Available in short acting forms for rapid blood pressure control and long acting for long-term maintenance therapy. May be used simultaneously with magnesium sulfate. May inhibit labor |
| Breast-feeding | No known evidence of harm (NICE). Second line after labetalol |
Manufacturers advise avoid; however recommended by SOGC. No known evidence of harm (NICE) |
Not for preterm infants. No known evidence of harm (NICE) Particularly for women needing cardiac/renal protection |
Manufacturers recommend avoid. Very small amounts in breast milk. No known evidence of harm (NICE) | No known evidence of harm (NICE) | Excreted in breast milk, at levels too low to be harmful | Manufacturers advise avoid, no known evidence of harm (NICE). Amounts in breast milk too small to be harmful. Second line: Amlodipine |
| Postnatal | Yes | Yes | Yes | Yes | NICE says avoid | Yes | Yes |
| Side-effects | Risk of fetal growth restriction and bradycardia in pregnancy | Cough | Cough | Tachycardia | Depression Reduced variability on CTG Methyldopa hepatitis |
Headache | |
| Contraindications | Asthma | Asthma | Mental health disorders Hepatic disease |
Abbreviations: ACE, angiotensin-converting enzyme; CTG, cardiotocography; NICE, National Institute for Health and Care Excellence; SOGC, Society of Obstetricians and Gynecologists of Canada.