Is amlodipine (calcium channel blocker) safe to use during pregnancy?

Amlodipine Safety in Pregnancy

Long-acting nifedipine is the preferred calcium channel blocker for hypertension during pregnancy, while amlodipine is not specifically recommended as a first-line agent despite limited data suggesting it may be safe. 1

Safety Profile of Amlodipine in Pregnancy

• The FDA label for amlodipine indicates limited available data from post-marketing reports with amlodipine use in pregnant women, which are not sufficient to inform a drug-associated risk for major birth defects and miscarriage 2
• Animal studies showed no evidence of adverse developmental effects at doses 10-20 times the maximum recommended human dose, though there were effects on litter size and gestation period in rats 2
• A 2019 study of 48 neonates exposed to amlodipine in the first trimester found no significant difference in birth defects compared to those exposed to other antihypertensives or no antihypertensives 3
• Amlodipine does cross the placenta in measurable quantities but was not detected in breast milk or infant plasma at 24-48 hours of life in a 2018 pharmacokinetic study 4

Recommended Antihypertensive Medications in Pregnancy

• Current guidelines specifically recommend methyldopa, labetalol, and long-acting nifedipine as first-line antihypertensive medications that are effective and safe in pregnancy 5, 1
• The 2025 Diabetes Care guidelines specifically mention long-acting nifedipine as a preferred calcium channel blocker for pregnancy, with no specific mention of amlodipine 5
• The 2024 European Society of Cardiology guidelines specifically recommend dihydropyridine CCBs (preferably extended-release nifedipine) as first-line BP-lowering medications for treating hypertension in pregnancy 5

Comparative Efficacy and Safety

• A 2022 meta-analysis comparing amlodipine to nifedipine found that amlodipine's efficacy was slightly superior to nifedipine for treating hypertension during pregnancy with decreased risk for maternal side effects 6
• The same meta-analysis found no difference between amlodipine and nifedipine on pregnancy outcomes including caesarean section, premature labor, placental abruption, fetal growth restriction, fetal distress, and neonatal asphyxia 6

Blood Pressure Management in Pregnancy

• Current evidence supports managing blood pressure to 110–135/85 mmHg during pregnancy to reduce the risk of accelerated maternal hypertension while minimizing impairment of fetal growth 5
• The Control of Hypertension in Pregnancy Study (CHIPS) found that aiming for a diastolic blood pressure of 85 mmHg during pregnancy was associated with reduced likelihood of developing accelerated maternal hypertension with no demonstrable adverse outcome for infants 5

Clinical Decision Algorithm for Antihypertensive Selection in Pregnancy

1. First-line options for hypertension in pregnancy:

   • Long-acting nifedipine (preferred calcium channel blocker) 5, 1
   • Labetalol 5, 1
   • Methyldopa 5, 1

2. If first-line agents are not tolerated or contraindicated:

   • Consider switching between first-line agents 1
   • Amlodipine may be considered as an alternative, though it has less established safety data 6, 3

3. Medications contraindicated in pregnancy:

   • ACE inhibitors 5
   • Angiotensin receptor blockers (ARBs) 5
   • Direct renin inhibitors 5
   • Mineralocorticoid receptor antagonists (MRAs) 5
   • Neprilysin inhibitors 5

Important Considerations and Pitfalls

• Avoid short-acting nifedipine for maintenance therapy in pregnancy as it can cause uncontrolled hypotension, particularly when combined with magnesium sulfate 1
• Be aware that nifedipine is available in multiple formulations; use only the long-acting formulation for maintenance therapy during pregnancy 1
• Diuretics are not recommended for blood pressure control in pregnancy but may be used during late-stage pregnancy if needed for volume management 5
• Postpartum monitoring is recommended for patients with gestational hypertension, preeclampsia, and superimposed preeclampsia (blood pressure observed for 72 hours in hospital and 7-10 days postpartum) 5