Drug Levels and Effects:

Summary of Use during Lactation:

Because of its relatively extensive excretion into breastmilk and its renal excretion, otherbeta-adrenergic blocking drugs are preferred to nadolol, especially while nursing a newborn or preterm infant.

Drug Levels:

The excretion ofbeta-adrenergic blocking drugs into breastmilk is largely determined by their protein binding. Those with low binding are more extensively excreted into breastmilk.[1] Accumulation of the drugs in the infant is related to the fraction excreted in urine. With 25% protein binding, 70% renal excretion and long half-life, nadolol presents a high risk for accumulation in infants, especially neonates. It is estimated that a fully breastfed infant would receive about 5.1% of the maternal weight-adjusted dosage of nadolol.[2]

Maternal Levels.

One mother received nadolol 20 mg daily during gestation for hypertension, with the last dose taken 20 hours before delivery. A single sample of breastmilk obtained 38 hours postpartum (58 hours after the last dose) was 146 mcg/L.[3]

After oral doses of 80 mg daily in 12 women, peak nadolol levels occurred in milk at an average of 6 hours after the dose, compared to peak serum levels at 2.7 hours. Serum and milk half-lives were both about 22 hours. Steady-state milk levels occurred after 3 days of therapy; peak milk levels averaged 443 mcg/L and the mean milk levels averaged 357 mcg/L. None of the infants were breastfed.[4][5]

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

A study of mothers takingbeta-blockers during nursing found a numerically, but not statistically significant increased number of adverse reactions in those taking anybeta-blocker. Although the ages of infants were matched to control infants, the ages of the affected infants were not stated. None of the mothers were taking nadolol.[6]

Possible Effects on Lactation:

Relevant published information on the effects ofbeta-blockade or nadolol during normal lactation was not found as of the revision date. A study in 6 patients with hyperprolactinemia and galactorrhea found no changes in serum prolactin levels followingbeta-adrenergic blockade with propranolol.[7]

Alternate Drugs to Consider:



1. Riant P, Urien S, Albengres E et al. High plasma protein binding as a parameter in the selection of betablockers for lactating women. Biochem Pharmacol. 1986;35:4579-81. PMID:2878668
2. Atkinson HC, Begg EJ, Darlow BA. Drugs in human milk. Clinical pharmacokinetic considerations. Clin Pharmacokinet. 1988;14:217-40. PMID:3292101
3. Fox RE, Marx C, Stark AR. Neonatal effects of maternal nadolol therapy. Am J Obstet Gynecol. 1985;152:1045-6. PMID:4025452
4. Devlin RG, Fleiss PM. Nadolol excretion in human milk. Clin Pharmacol Ther. 1981;29:240. Abstract.
5. Devlin RG, Duchin KL, Fleiss PM. Nadolol in human serum and breast milk. Br J Clin Pharmacol. 1981;12:393-6. PMID:6117304
6. Ho TK, Moretti ME, Schaeffer JK et al. Maternalbeta-blocker usage and breast feeding in the neonate. Pediatr Res. 1999;45:67A. Abstract 385.
7. Board JA, Fierro RJ, Wasserman AJ et al. Effects of alpha- andbeta-adrenergic blocking agents on serum prolactin levels in women with hyperprolactinemia and galactorrhea. Am J Obstet Gynecol. 1977;127:285-7. PMID:556882

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antihypertensive Agents

  • Adrenergic
  • Beta
  • -Antagonists

  • Antiarrhythmics

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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