What is the recommended management of pulmonary tuberculosis in a pregnant woman?

Management of Pulmonary Tuberculosis in Pregnancy

Pregnant women with pulmonary tuberculosis should be treated immediately with isoniazid, rifampin, and ethambutol for 9 months, along with pyridoxine 25 mg daily, as untreated tuberculosis poses far greater risks to both mother and fetus than the medications. 1

Initial Treatment Regimen

• Start treatment without delay upon diagnosis, as untreated tuberculosis carries significantly higher maternal and fetal morbidity and mortality than the treatment itself 1, 2
• The standard regimen consists of isoniazid, rifampin, and ethambutol given daily 1, 3
• Pyridoxine (vitamin B6) 25 mg daily must be added to all pregnant women receiving isoniazid to prevent peripheral neurotoxicity 1, 4
• Treatment duration is 9 months minimum when pyrazinamide is excluded from the regimen 1

Critical Medications to Avoid

• Streptomycin and all aminoglycosides (kanamycin, amikacin) are absolutely contraindicated in pregnancy, as they cause congenital deafness in approximately 17% of exposed fetuses 5, 1, 3
• Pyrazinamide is generally not recommended in the United States due to insufficient teratogenicity data, though WHO and other international organizations do endorse its use 1, 6
• Fluoroquinolones should be avoided when possible due to association with arthropathies in animal studies 1
• Ethionamide and prothionamide may be teratogenic and should be avoided 5

Monitoring During Treatment

• Obtain baseline liver function tests before initiating therapy 1
• Monitor liver enzymes closely during the first two months, particularly at weeks 2,4, and 8, as pregnancy may increase vulnerability to isoniazid hepatotoxicity 5, 1
• Educate the patient to stop treatment immediately and seek evaluation if symptoms of hepatitis develop (nausea, vomiting, abdominal pain, jaundice) 1
• Monthly clinical evaluations are required to assess for side effects and treatment adherence 1

Special Considerations for Drug Interactions

• Rifampin reduces the efficacy of oral contraceptives, so alternative contraception methods should be discussed 5
• If the patient is on corticosteroids for other conditions, double the maintenance dose due to rifampin's enzyme induction effects 5
• For diabetic patients, oral hypoglycemic doses may need to be increased due to rifampin interaction 6

Breastfeeding Guidance

• Breastfeeding should not be discouraged in women taking first-line antituberculosis drugs, as concentrations in breast milk are too low to cause toxicity 5, 1
• However, drugs in breast milk cannot be considered effective treatment for the nursing infant if the infant requires tuberculosis therapy 1

Pregnancy-Specific Reassurance

• Pregnancy is not an indication for termination in women taking rifampin or other first-line antituberculosis drugs 5, 1, 3
• None of the first-line drugs (isoniazid, rifampin, ethambutol) have been shown to be teratogenic in humans 5, 4
• Standard treatment can be given safely throughout all trimesters 5, 1

Multidrug-Resistant Tuberculosis

• Consultation with a tuberculosis expert is mandatory for MDR-TB cases, as treatment must be based on susceptibility studies 1
• Second-line drugs have varying safety profiles; ciprofloxacin has the best safety record among fluoroquinolones if absolutely necessary 4
• Some second-line drugs are teratogenic and must be used with extreme caution 2, 7

Common Pitfalls to Avoid

• Never delay treatment waiting for the second trimester or postpartum period—the risks of untreated tuberculosis far exceed medication risks 1, 2
• Do not use streptomycin even if drug resistance is suspected; choose alternative second-line agents 5, 1
• Do not forget pyridoxine supplementation—this is mandatory, not optional, in pregnant women on isoniazid 1, 4
• Do not assume pregnancy increases tuberculosis progression risk—it does not, but hepatotoxicity monitoring remains crucial 1, 8