Drug Levels and Effects:

Summary of Use during Lactation:

Limited information indicates that maternal pyrazinamide therapy produces low levels in milk and would not usually be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Exclusively breastfed infants should be monitored for rare cases of jaundice, hepatitis and arthralgia if this drug is used during lactation.[1] The amount of pyrazinamide in milk is insufficient to treat tuberculosis in the breastfed infant. The Centers for Disease Control and Prevention and other professional organizations state that breastfeeding should not be discouraged in women taking pyrazinamide .[2][3][4]

Drug Levels:

Maternal Levels.

One woman who was lactating, but not breastfeeding (time postpartum not stated) was given a single oral dose of 1 gram of pyrazinamide . A peak milk level of 1.5 mg/L occurred 3 hours after the dose. The half-life of the drug in milk was estimated to be 9 hours.[1] Using these data, a fully breastfed infant would receive a maximum of about 1.4% of the maternal weight-adjusted dosage.

Infant Levels.

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

Effects in Breastfed Infants:

Pyrazinamidewas used as part of multi-drug regimens to treat 2 pregnant women with multidrug-resistant tuberculosis throughout pregnancy and postpartum. Their two infants were breastfed (extent and duration not stated). At age 1.25 and 5.1 years, the children were developing normally.[5]

Possible Effects on Lactation:

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


1. Holdiness MR. Antituberculosis drugs and breast-feeding. Arch Intern Med. 1984;144:1888. Letter. PMID:6548112
2. Blumberg HM, Burman WJ, Chaisson RE et al. American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: treatment of tuberculosis. Am J Respir Crit Care Med. 2003;167:603-62. PMID:12588714
3. Anon. Treatment of tuberculosis. MMWR Recomm Rep. 2003;52:1-77. PMID:12836625
4. Bartlett JG. Guidelines section. Infect Dis Clin Pract. 2002;11:467-71.
5. Drobac PC, del Castillo H, Sweetland A et al. Treatment of multidrug-resistant tuberculosis during pregnancy: long-term follow-up of 6 children with intrauterine exposure to second-line agents. Clin Infect Dis. 2005;40:1689-92. PMID:15889370

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antitubercular Agents

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

    Disclaimer:Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.