Is Nifedipine safe while breastfeeding?

Effects on the breastfed infant

No adverse reactions have been reported among infants exposed to nifedipine in breastmilk mostly at maternal dosages of 30 mg daily beginning shortly postpartum and continuing for up to 6 months in some.[ 2 , 7 , 12 - 18 ]

Effects on milk supply

No direct effects are known. However, nifedipine has been used to decrease the pain of nipple vasospasm (or Raynaud phenomenon of the nipple), allowing mothers to continue nursing who might otherwise discontinue breastfeeding.[ 1 , 2 , 4 , 13 - 16 , 18 - 21 ] Nifedipine had no effect on milk composition (sodium, potassium, calcium, chloride, nitrogen, phosphorus and total lipids) in one woman.[ 8 ] In a pilot study of the treatment of patients with postpartum hypertension, patients were randomized to either 12.5 mg hydrochlorothiazide plus 10 mg of lisinopril (n = 31) or 30 mg of nifedipine (n = 36) daily. The dosages could be increased to 12.5 mg hydrochlorothiazide plus 20 mg of lisinopril and then to 25 mg hydrochlorothiazide with 20 mg lisinopril. Nifedipine dosage was increased in 30 mg increments to a maximum daily dose of 120 mg daily. At discharge, 21 hydrochlorothiazide-lisinopril mothers (70%) were breastfeeding while19 nifedipine mothers (53%) were breastfeeding.[ 22 ]

Levels in milk

Maternal Levels. A woman taking nifedipine 10 mg four times daily was given a 20 mg test dose 10 days postpartum. One hour after this dose, peak milk levels of the drug and its pyridine metabolite were 43 and 15 mcg/L, respectively. By 4 hours after the dose, the levels of both drugs in breastmilk were less than 5 mcg/L.[ 7 ] Another woman took doses of 10, 20 and 30 mg every 8 hours on different days shortly after delivering a premature infant. Her peak milk nifedipine levels occurred 1 hour after each dose. The half-life of the drug in milk varied with dosage: 1.4 hours with the 10 mg dose; 3.1 hours with the 20 mg dose; and 2.4 hours with the 30 mg dose. The average milk half-life of all doses was 3.3 hours. The highest milk level found was 53 mcg/L at 30 minutes after the 30 mg dose. Nifedipine had fallen to undetectable levels ( 2 mcg/L) by 5.25 hours after the 10 mg dose. At 8 hours after the dose, nifedipine concentrations in milk were 3.2 mcg/L with the 20 mg dose and 4.9 mcg/L with the 30 mg dose. The total amounts in milk collected over 24 hours were 0.12 mcg with 10 mg every 8 hours, an average of 1.07 mcg with 20 mg every 8 hours, and an average of 1.71 mcg with 30 mg every 8 hours. Using the peak milk level data from the 30 mg every 8 hour dosage in this study, the authors estimated that an exclusively breastfed infant would receive an estimated maximum of 7.5 mcg/kg daily with this maternal dosage regimen.[ 8 ] In 6 women taking a dose of 10 mg three times daily, milk levels ranged from 1 to 10.3 mcg/L at random times between 1 and 8 hours after a dose, with a median of 3.5 mcg/L.[ 9 ] In a study of 21 women taking a median dosage of 40 mg daily, mostly as a sustained-release product, 13 donated milk samples at a median of 7 days postpartum (range 1 to 100 days). The infants would receive an average daily dosage of 0.1% of their mother's weight-adjusted dosage in breast milk.[ 10 ] Nineteen hypertensive nursing mothers taking 20 mg of slow-release nife

Alternatives LactMed lists

• Amlodipine
• Nitrendipine