The second option is for the patient to take isoniazid, rifampin, pyrazinamides, and ethambutol or streptomycin daily for two weeks. After the two weeks then the patient may take all four of the medications twice a week for six weeks. The next step is to then take isoniazid and rifampin twice a week for sixteen weeks. The third option is isoniazid, rifampin, pyrazinamides, and ethambutol or streptomycin three times a week for twenty-four weeks. When a patient is taking intermittent doses of the medications they are having directly observed therapy.
Intermittent regimens are equally effective to daily regimens.
Directly observed therapy allows therapy to be more feasible and more cost efficient than a daily regimen. Directly observed therapy has been found to be more effective than self-administered therapy. It also results in lower rates of relapse, emergence of drug resistance, and in HIV positive patients, death. While a person is receiving drug therapy for tuberculosis it is important to monitor for compliance, treatment response, toxicity development, and signs of treatment failure. It is important to remember that response to treatment may be slow.