Summary of Use during Lactation

Limited information indicates that there are low levels of rifampin in breastmilk that would not be expected to cause any adverse effects in breastfed infants. The amount of rifampin 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 rifampin.[1-3] Breastmilk may be stained a yellow, orange, red or brown color.

Drug Levels

Maternal Levels. One old study reported that after a single oral dose of rifampin of 150 mg, milk levels 4 hours after the dose ranged from 0 to 1.8 mg/L. After a single oral dose of 450 mg, milk levels 12 hours after the dose ranged from 3.4 to 4.9 mg/L.[4] Details of the study and patients were not stated.

A physiologically based pharmacokinetic model of rifampin predicted that a fully breastfed infant would receive a dose of 0.4 mg/kg daily with a maternal dosage of 10.9 mg/kg daily, which is 3.7% of the weight-adjusted maternal dosage.[5]

Among a group of women taking rifampin for tuberculosis, 65 breastmilk samples were taken. Twenty-seven were below the limits of quantification. Of the other samples, the peak concentrations in milk occurred at 3.33 hours and 4.8 hours in the intensive and maintenance phase visits, respectively. Peak milk concentrations were typically about 1 mg/L.[6]

Infant Levels. Measured infant serum levels have not been reported. A physiologically based pharmacokinetic model of rifampin predicted that a fully breastfed infant would achieve a maximum serum concentration of about 0.2 mg/L with a maternal dose of 10.9 mg/kg daily.[5]

In a study of mothers taking rifampin (dose not stated) for tuberculosis, one breastfed infant had a rifampin serum concentration of 2.93 mg/L at 6 hours after a maternal dose.[6]

Effects in Breastfed Infants

One woman taking rifampin 450 mg, isoniazid 300 mg and ethambutol 1200 mg daily during pregnancy and rifampin 450 mg and isoniazid 300 mg for the first 7 months of lactation (extent not stated). The infant was born with mildly elevated serum liver enzymes which persisted for to 1 (alanine transferase) to 2 years (aspartate transaminase), but had no other adverse reactions.[7]

Rifampin was 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 3.9 and 5.1 years, the children were developing normally except for hyperactivity in one.[8]

Two mothers in Türkiye were diagnosed with tuberculosis at the 30th and 34th weeks of pregnancy. They immediately started isoniazid 300 mg, rifampin 600 mg, pyridoxine 50 mg daily for 6 months, plus pyrazinamide 25 mg/kg and ethambutol 25 mg/kg daily for 2 months. Both mothers breastfed their infants (extent not stated). Their infants were given isoniazid 5 mg/kg daily for 3 months prophylactically. Tuberculin skin tests were negative after 3 months and neither infant had tuberculosis at 1 year of age. No adverse effects of the drugs were mentioned.[9]

A woman with leprosy took clofazimine, dapsone and rifampin during pregnancy and breastfeeding. Her infant developed skin discoloration attributed to clofazimine which reversed 3 months after cessation of breastfeeding.[10]

Effects on Lactation and Breastmilk

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

Alternate Drugs to Consider

(Methicillin-resistant Staph. aureus) Doxycycline, Minocycline, Trimethoprim-Sulfamethoxazole, Vancomycin; (M. tuberculosis) Rifapentine

References

1.

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. [PubMed: 12588714]

2.

Anon. Treatment of tuberculosis. MMWR Recomm Rep 2003;52:1-77. [PubMed: 12836625]

3.

Bartlett JG. Guidelines section. Infect Dis Clin Pract 2002;11:467-71. doi:10.1097/01.idc.0000086415.30743.15 [CrossRef]

4.

Lenzi E, Santauri S. Preliminary observations on the use of a synthetic rifamycin derivative. Atti Accad Lancisiana Roma 1969;13 (Suppl 1):87-94.

5.

Partosch F, Mielke H, Stahlmann R, et al. Exposure of nursed infants to maternal treatment with ethambutol and rifampicin. Basic Clin Pharmacol Toxicol 2018;123:213-20. [PubMed: 29505119]

6.

Ojara FW, Kawuma AN, Nakijoba R, et al. Pharmacokinetics of rifampicin, used in treatment of drug-sensitive tuberculosis in breastfeeding mother-infant pairs: An interim analysis based on six mother-infant pairs. Br J Pharmacol 2023;180:355-6. doi:10.1111/bph.16106 [CrossRef]

7.

Peters C, Nienhaus A. [Case report--tuberculosis in a health care worker during pregnancy]. Pneumologie 2008;62:695-8. [PubMed: 18855309]

8.

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. [PubMed: 15889370]

9.

Keskin N, Yilmaz S. Pregnancy and tuberculosis: To assess tuberculosis cases in pregnancy in a developing region retrospectively and two case reports. Arch Gynecol Obstet 2008;278:451-5. [PubMed: 18273625]

10.

Ozturk Z, Tatliparmak A. Leprosy treatment during pregnancy and breastfeeding: A case report and brief review of literature. Dermatol Ther 2017;30:e12414. [PubMed: 27549245]

Substance Name

Rifampin

CAS Registry Number

13292-46-1

Drug Class

Breast Feeding

Lactation

Milk, Human

Anti-infective Agents

Antitubercular Agents

Leprostatic Agents

Rifamycins