Chart 4. Management of treatment interruptions.

Interruption time point	Details of interruption	Approach
During the intensive phase	Lapse is < 14 days in duration	Continue treatment to complete the planned total number of doses (60 doses), as long as the intensive phase lasts 3 months at most
	Lapse is ≥ 14 days in duration	Restart treatment from the beginning
During the maintenance phase	Received ≥ 80% of the doses and was smear-negativeb	Continue treatment. The patient may not need to take all doses
	Received ≥ 80% of the doses and was smear-positive at the start of treatment	Continue treatment until all 120 doses are completed
	Received < 80% of the doses, and accumulative lapse is < 3 months in duration	Continue treatment until all 120 doses are completed, unless consecutive lapse is > 2 months in duration. In such cases, restart treatment. If treatment cannot be completed within 9 months (with the intensive phase lasting 3 months at most and the maintenance phase lasting 6 months at most), restart treatment from the beginning of the intensive phase.
	Received < 80% of the doses, and accumulative lapse is ≥ 3 months in duration	Restart treatment from the beginning (new intensive and maintenance phases)

aSmear microscopy, culture, and susceptibility testing should always be performed when patients resume treatment. bSmear-negative patient: a patient with at least two AFB-negative sputum samples (including one sample collected in the morning); X-ray findings consistent with tuberculosis and/or no clinical response to treatment with broad-spectrum antimicrobial agents (Note: fluoroquinolones should not be used because they have activity against the Mycobacterium tuberculosis complex and can produce transient improvement in patients with tuberculosis); satisfactory response to antituberculosis treatment.