The American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), and Infectious Diseases Society of America (IDSA) developed an algorithm for the treatment of a patient who has a high clinical suspicion for active tuberculosis.
NOTE: This algorithm assumes that the risk of a multidrug-drug resistant strain is very low. The initial drug choices and the durations of therapy would be different for a multidrug-resistant strain.
Parameters affecting therapy choices:
(1) susceptibility testing on initial isolate
(2) cavitation on chest X-ray at 2months
(3) AFB (acid fast bacilli) smear at 2 months
(4) AFB culture at 2 months
Initial therapy is 2 months of:
(1) isoniazid (INH)
(2) rifampin (RIF)
(3) ethambutol (EMB)
(4) pyrazinamide (PZA)
Ethambutol is discontinued if susceptibility testing on the initial isolate shows that it is susceptible to the other drugs.
Pyrazinamide is discontinued after 2 months (56 doses).
The patient is evaluated at 2 months. Continuation of therapy depends on findings at this evaluation.
|
Cavitation at 2 Months |
Sputum Smear at 2 Months |
Sputum Culture at 2 Months |
Therapeutic Regimen |
|
positive |
negative |
negative |
A |
|
positive |
negative |
positive |
B |
|
positive |
positive |
negative |
A |
|
positive |
positive |
positive |
B |
|
negative |
negative |
negative |
A or C |
|
negative |
negative |
positive |
A or D |
|
negative |
positive |
negative |
A |
|
negative |
positive |
positive |
B |
|
Regimen |
Additional Duration of Therapy |
Drugs |
|
A |
4 months (total 6) |
INH and RIF |
|
B |
7 months (total 9) |
INH and RIF |
|
C |
4 months (total 6) |
INH and rifapentine (see below) |
|
D |
7 months (total 9) |
INH and rifapentine (see below) |
Do not use rifapentine if one or both of the following is present:
(1) the patient is HIV-positive
(2) the patient has extrapulmonary tuberculosis.
|
Regimen |
HIV positive and CD4 lymphocyte count < 100 per µL |
Extrapulmonary TB OR other HIV positive |
Other Patients |
|
A |
daily or three times weekly |
daily or twice weekly |
daily or twice weekly |
|
B |
daily or three times weekly |
daily or twice weekly |
daily or twice weekly |
|
C |
do not use |
do not use |
once weekly |
|
D |
do not use |
do not use |
once weekly |
Specialty: Infectious Diseases, Pharmacology, clinical, Pulmonology
