Drug treatment for tuberculosis during pregnancy: safety considerations

Untreated tuberculosis in pregnancy poses a significant threat to the mother, fetus and family. Adherence to treatment is especially difficult in pregnancy because of the general fear of any medication and pregnancy-related nausea. Supervised treatment is especially helpful in encouraging adherence. All 4 first line drugs [isoniazid, rifampicin (rifampin), ethambutol and pyrazinamide] have an excellent safety record in pregnancy and are not associated with human fetal malformations. Drug-induced hepatitis, especially with isoniazid, is a significant problem in treating tuberculosis, not peculiar to pregnancy; close monitoring of liver function is recommended. Liver enzyme induction by rifampicin alters the metabolism of other drugs, e.g. methadone doses will need to be increased. Streptomycin should not be used in pregnancy, as perhaps 1 in 6 babies will have problems with hearing and/or balance. Ciprofloxacin has the best safety profile of second line drugs in the treatment of drug-resistant tuberculosis. Preventive treatment with isoniazid can be undertaken safely during pregnancy. Pyridoxine (vitamin B6) should be added to the drug treatment of tuberculosis in all pregnant women taking isoniazid. Neither tuberculin nor the bacille Calmette Guérin (BCG) vaccine are treatments for tuberculosis, but they play an important role in the management of the disease. Tuberculin testing is safe, but BCG vaccination should be avoided in pregnancy and instead given earlier in life.