Table II.
Antihypertensive Drug Excretion in Breast Milk
| Drug | Daily Dose, mg | Average Concentration in Milk | Milk to Plasma Ratio | Transfer to Infant |
|---|---|---|---|---|
| Atenolol | 100 | 0.6 μg/mL | 3.0 | 10 μg/mL; may induce neonatal depression |
| Captopril | 300 | 5.0 μg/mL | 0.1 | Not studied |
| Chlorthalidone | 50 | 0.3 ng/mL | 0.05 | Not studied |
| Clonidine | 0.15 | 1.5 ng/mL | 1.5 | Not studied |
| Diltiazem | 240 | 200.0 ng/mL | 1.0 | Not studied |
| Enalapril | 20 | 1.74 ng/mL | 0.01 | Not studied |
| Hydralazine | 150 | 0.8 μg/mL | 0.5 | Not studied |
| Hydrochlorothiazide | 50 | 100.0 ng/mL | 0.4 | Not detected (<1 ng/mL) |
| Methyldopa | 1000 | 1.0 μg/mL | 0.3 | Plasma level of 0.09 μg/mL; no adverse effects noted |
| Metoprolol | 200 | 1.7 μg/mL | 3.0 | Not studied |
| Nadolol | 80 | 0.35 μg/mL | 5.0 | Not reported |
| Nicardipine (intravenous) | 4.5–5.5 mg/h | 5.1–18.5 ng/mL | Not reported | <300 ng/d was estimated |
| Nifedipine | 90 | 10 ng/mL | – | Not studied |
| Nitrendipine | 10 | 5.0 ng/mL | 2.5 | Not studied |
| Oxprenolol | 160 | 130.0 ng/mL | 0.3 | Not elevated |
| Quinapril (quinaprilat) | 20 | 27.9 μg/L/d | 0.12 | Estimated at 1.6% of maternal dose |
| Propranolol | 160 | 50.0 ng/mL | 0.6 | No adverse effects noted |
| Sotalol | 160 | 4 μg/mL | 5.6 | Not studied |
| Timolol | 15 | 16.0 ng/mL | 0.8 | Not studied |
| Verapamil | 240 | 20.0 μg/mL | 0.4 | Not detected in infants’ plasma |