What tuberculosis (TB) medications are safe for pregnant women?

Safe Tuberculosis Medications for Pregnant Women

For pregnant women with tuberculosis, the initial treatment regimen should consist of isoniazid, rifampin, and ethambutol, as these medications are considered safe during pregnancy and do not cause fetal malformations. 1, 2

First-Line TB Medications in Pregnancy

Safe Medications

• Isoniazid (INH): Safe during pregnancy with no evidence of teratogenicity even when given during the first trimester 1, 2

  • Should be supplemented with pyridoxine (vitamin B6, 25 mg/day) to prevent neurotoxicity in both mother and fetus 1, 3
  • Requires monthly liver function monitoring as pregnancy may increase vulnerability to isoniazid hepatotoxicity 4, 2

• Rifampin: Generally considered safe during pregnancy despite some concerns in animal studies 4, 3

  • Clinical experience shows no significant increase in birth defects in humans 1, 5
  • Note that rifampin reduces the efficacy of oral contraceptives due to enzyme induction 4

• Ethambutol: Safe during pregnancy with no significant evidence of teratogenicity 1, 6

  • No reported ophthalmic toxicity in fetuses when mothers receive standard doses 3, 7

Medications to Avoid

• Streptomycin and other aminoglycosides (kanamycin, amikacin): Should be avoided during pregnancy as they can cause congenital deafness in approximately 17% of exposed fetuses 1, 7

• Pyrazinamide: Generally not recommended in the United States during pregnancy due to insufficient teratogenicity data 1, 8

  • Some international guidelines do include pyrazinamide in pregnancy regimens, but U.S. guidelines recommend avoiding it if possible 1

• Fluoroquinolones: Should be avoided if possible during pregnancy due to their association with arthropathies in animal studies 1

Treatment Duration and Regimen

• If pyrazinamide is not included in the treatment regimen (as is typical in the U.S.), the minimum duration of therapy should be 9 months 1, 3
• The 9-month regimen typically consists of:
  • Isoniazid and rifampin throughout the entire treatment course
  • Ethambutol during the initial phase until drug susceptibility is confirmed 1, 5

Monitoring During Treatment

• Baseline liver function tests should be obtained for all pregnant women before starting TB treatment 4, 2
• Monthly monitoring of liver function is recommended during treatment, particularly in the first two months 4, 2
• Regular clinical evaluation for signs of hepatitis and other adverse effects 4

Special Considerations

• Treatment should be started without delay as untreated tuberculosis poses a greater risk to both mother and fetus than the medications 1, 3
• For latent TB infection (LTBI) in pregnancy, isoniazid given daily or twice weekly for 9 or 6 months is recommended 4
• For women at high risk for progression of LTBI to active disease (especially those with HIV infection or recent infection), treatment should not be delayed due to pregnancy, even during the first trimester 4
• For women with lower risk of TB progression, some experts recommend waiting until after delivery to start LTBI treatment 4

Breastfeeding Considerations

• Breastfeeding is not contraindicated for women being treated with first-line anti-tuberculosis drugs 4, 8
• The small concentrations of these drugs in breast milk do not produce toxic effects in the nursing infant 2, 8
• Infants whose breastfeeding mothers are taking isoniazid should receive supplemental pyridoxine 4
• The amount of medication in breast milk is inadequate for treatment of tuberculosis in the infant 4, 2

Important Pitfalls to Avoid

• Delaying treatment of active TB due to pregnancy concerns - this poses greater risk than the medications 1, 3
• Failing to provide pyridoxine supplementation with isoniazid 1, 3
• Inadequate monitoring of liver function during treatment 4, 2
• Using streptomycin or other aminoglycosides during pregnancy 1, 7
• Termination of pregnancy is not medically indicated for women taking first-line anti-tuberculosis drugs 1, 7