TB Facts for Health Care Workers
Multidrug-Resistant Tuberculosis (MDR TB)
An extremely serious aspect of the TB problem in the United States
is MDR TB (i.e., TB resistant to at least isoniazid and rifampin).
MDR TB can usually be prevented by initially treating TB patients
with four drugs and by administering TB medications on a directly
observed basis. Persons at high risk for MDR TB include persons
who have been recently exposed to MDR TB, especially if they are
immunocompromised; TB patients who failed to take medications
as prescribed; TB patients who were prescribed an ineffective
treatment regimen; and persons previously treated for TB.
MDR TB presents difficult treatment problems. Treatment must
be individualized and based on the patientís medication history
and drug susceptibility study results. Clinicians who are not
familiar with the management of patients with MDR TB disease or
with patients infected with multidrug-resistant organisms should
seek expert consultation.
For persons likely to have been infected with M. tuberculosis
resistant to both isoniazid and rifampin, observation without
preventive therapy is usually recommended because only isoniazid
and rifampin have been evaluated for preventive therapy. However,
for persons at an especially high risk for TB disease once infected
(e.g., persons with HIV infection), preventive therapy with an
alternative regimen should be strongly considered.