TB Facts for Health Care Workers
Treatment of Tuberculosis
Regimens for the Treatment of Tuberculosis
TB is usually curable if effective treatment is instituted without
delay. TB treatment regimens must contain multiple drugs to which
the organisms are susceptible. Treatment with a single drug can
lead to the development of a bacterial population resistant to that
drug. Likewise, the addition of a single drug to a failing antituberculosis
regimen can lead to resistance to that drug.
There are four basic regimens* recommended for treating adults
with culture-positive TB caused by organisms that are known or presumed
to be susceptible to INH, RIF, PZA, and ethambutol (EMB). Each treatment
regimen consists of an initial 2-month treatment phase followed
by a continuation phase. The continuation phase is generally 4 months
for the majority of patients. All TB drugs should be given together
rather than in divided doses.
The continuation phase should be extended to 7 months for a total
of 9 months (an additional 3 months) for patients
- Who have cavitary pulmonary TB on a chest radiograph at diagnosis
and positive sputum cultures at completion of the initial phase;
- Whose initial phase of treatment did not include PZA; or
- Who are being treated with once-weekly INH and rifapentine (RPT)
(only in HIV-negative patients without cavitation for pulmonary
disease) and whose sputum culture is positive at completion of
the initial phase.
Treatment completion is determined primarily by the number of doses
ingested within a specified time frame. The duration of therapy
depends on the drugs used, the drug susceptibility test results,
and the patient’s response to therapy. All 6-month regimens must
contain INH, RIF, and initially, PZA; all regimens of 9 months or
less must contain INH and RIF.
Management of HIV-related TB disease is complex, and the clinical
and public health consequences associated with the failure of treatment
are serious. The care for HIV-related TB should be provided by or
in consultation with experts in the management of both TB and HIV
disease. Every effort should be made to use a rifamycin-based regimen
for the entire course of therapy.
Recommendations for the treatment of TB in HIV-infected adults are
the same as for HIV-negative patients, with two exceptions:
- Once-weekly administration of INH/rifapentene in the continuation
phase should not be used in any HIV-positive
- Twice-weekly administration of INH/RIF or rifabutin in the continuation
phase should not be used for patients with CD4+
lymphocyte counts less than 100/µl
*Although these regimens are broadly applicable, there are modifications
that should be made under specified circumstances. Please refer
of Tuberculosis, MMWR 2003;
52(No. RR-11) for detailed information on TB treatment regimens.
A major cause of treatment failure and drug-resistant TB is nonadherence
to treatment. Treatment failure and drug-resistant TB threaten the
health of TB patients. These factors also pose serious public health
risks because they can lead to prolonged infectiousness and the
transmission of TB within the community.
One way to ensure that patients adhere to therapy is to use directly
observed therapy (DOT). DOT means that a health care worker or another
designated person watches the patient swallow each dose of TB medication.
DOT should be considered for all patients because clinicians are
often inaccurate in predicting which patients will adhere to medication
on their own.
In many areas, patients are routinely given DOT. DOT has been shown
to be cost-effective when intermittent regimens are used. Nearly
all the treatment regimens for drug-susceptible TB can be given
intermittently if they are directly observed; using intermittent
regimens reduces the total number of doses a patient must take,
as well as the total number of encounters with the health care provider
or outreach worker. Furthermore, DOT can significantly reduce the
frequency of acquired drug resistance and relapse.
Other measures commonly used to promote adherence:
- Developing an individualized treatment plan for each patient
- Working with outreach staff from the same cultural and linguistic
background as the patient
- Educating the patient about TB medication dosages and possible
- Using incentives and enablers to remove barriers to adherence
(e.g., transportation tokens and food vouchers)
- Facilitating access to health and social services