First-Line Treatment Regimen for Tuberculosis in Pregnancy
The recommended first-line treatment regimen for tuberculosis in pregnancy consists of isoniazid, rifampin, and ethambutol, which should be initiated without delay as untreated tuberculosis poses greater risks to both mother and fetus than the medications. 1
Core Treatment Components
- The initial treatment regimen should include isoniazid, rifampin, and ethambutol as these medications have excellent safety profiles in pregnancy and are not associated with human fetal malformations 1, 2
- Pyridoxine (vitamin B6) supplementation (25 mg/day) must be given to all pregnant women receiving isoniazid to prevent neurotoxicity 1, 2
- If pyrazinamide is not included in the treatment regimen (as is common practice in the US), the minimum duration of therapy should be 9 months 1
- The 9-month regimen typically consists of isoniazid and rifampin throughout, with ethambutol in the initial phase until drug susceptibility is confirmed 1
Medications to Avoid in Pregnancy
- Streptomycin and other aminoglycosides (kanamycin, amikacin) must be avoided during pregnancy as they can cause congenital deafness in approximately 17% of exposed fetuses 1, 3
- Pyrazinamide is generally not recommended in pregnancy in the United States due to insufficient teratogenicity data, although international organizations do recommend its routine use 1, 4
- Fluoroquinolones should be avoided if possible during pregnancy due to their association with arthropathies in young animals 1
Monitoring During Treatment
- Close monitoring of liver function is essential, with baseline liver function tests followed by regular monitoring, particularly during the first two months of treatment 1, 2
- Monthly clinical evaluations should include questioning about side effects and a brief physical assessment checking for signs of hepatitis 5, 1
- Patients should be educated about potential side effects and advised to stop treatment and promptly seek medical evaluation if concerning symptoms develop 5
Special Considerations
- Treatment should be started without delay, as untreated tuberculosis poses a greater risk to both mother and fetus than the medications 1, 2
- Adherence to treatment may be especially difficult in pregnancy due to fear of medication and pregnancy-related nausea; supervised treatment (DOTS) can be helpful in encouraging adherence 2
- For women with diabetes mellitus and tuberculosis, strict control of blood glucose is mandatory, and doses of oral hypoglycemic agents may need to be increased due to interaction with rifampin 6
- Breastfeeding should not be discouraged for women being treated with first-line anti-tuberculosis drugs, as the small concentrations in breast milk do not produce toxic effects in the nursing infant 1, 4
- For multidrug-resistant tuberculosis (MDR-TB), consultation with an expert in tuberculosis management is recommended 1, 6
Important Caveats
- Before initiating treatment, active TB must be ruled out through history, physical examination, chest radiography, and when indicated, bacteriologic studies 5, 7
- Termination of pregnancy is not medically indicated for women taking first-line anti-tuberculosis drugs 3
- Drug-induced hepatitis, especially with isoniazid, is a significant concern in treating tuberculosis and not specific to pregnancy; close monitoring of liver function is essential 2
- Rifampin induces liver enzymes and alters the metabolism of other drugs, which may require dose adjustments of concurrent medications 2