Last Updated on August 18, 2023
DOTS Therapy for Tuberculosis
DOTS therapy stands for directly observed treatment short-course therapy. It is a method of treatment of tubercular disease where the treatment is given according to the category of the patient and is directly supervised. It has been included in the national program in India and is carried out by various DOTS centers.
Categories of DOTS
DOTS divides the patient into four DOTS categories and the treatment is dependent upon which DOTS category patient is in.
Category I
- Freshly diagnosed smear-positive pulmonary tuberculosis
- Smear-negative pulmonary tuberculosis with extensive parenchymal involvement
- New cases with severe forms of tuberculosis e.g. miliary tuberculosis, tuberculous meningitis, tuberculous pericarditis, tuberculous peritonitis, intestinal TB, genitourinary TB, bilateral or extensive tuberculous pleurisy, spinal disease with neurological complications.
Category II
- Relapsed and treatment failure (smear-positive) cases
- Treatment after a substantial interruption.
These patients are at risk of developing multidrug-resistant tuberculosis (MDR-TB)
Category III
- Freshly diagnosed smear-negative pulmonary TB with limited parenchymal involvement
(pulmonary disease is almost always smear-negative in children; adolescents with primary TB may present with a smear-negative small parenchymal lung lesion or a small pleural effusion)
- Non-category I extrapulmonary tuberculosis.
Category wise Treatment in DOTS
The treatment in Category I consists of an intensive phase of isoniazid (H), rifampicin (R), Pyraziamide (Z) and ethambutol (E) administered under a direct supervision thrice weekly on alternate days for 2 months (24 dosages), followed by a continuation phase of H and R thrice weekly on alternate days for 4 months (18 weeks, 54dosages). The first dose of each week given directly supervised and the patient self-administering the next two doses of the week, at home.
In category II intensive phase consists streptomycin (S), H, R, Z and E for 2 months followed by 1 month of H, R, Z and E (total 36 dosages), is administered in the same supervised manner as Category I and is followed by an appropriately supervised continuation phase consisting of 5 months (22 weeks, 66 dosages) of H, R and E.
Category III treatment is similar to that of Category I, but is executed without an inclusion of ethambutol.
Supervision In DOTS In India
For the sake of convenience, the drugs are dispensed in category-wise boxes that are prepared at the start of therapy itself. Each box contains drugs in different blister packs.
The pack’ for an intensive phase consists of one day’s medications, while that for the continuation phase contains one week’s supply.
The drug administration days are fixed for a particular patient and either a Monday-Wednesday-Friday or a Tuesday-Thursday-Saturday.
If the patient ‘misses’ a dose, he must be contacted within a day of the missed dose during an intensive phase and within a week of the missed dose during the continuation phase.
The first dose of each week is administered under direct supervision, and the next 2 doses of week supplied to the patient following his presentation of the empty blister pack of consumed drugs of the previous week.
Follow Up
Category 1
Sputum examination is done at 2, 4 and 6 months of treatment. If the smear is positive after 2 months, the intensive phase is extended for one more month and sputum examinations were done at 3, 5 and 7 months.
Category II
Sputum smear examination is performed at 3, 5 and 8 months of treatment. If the smear is positive after 3 months, the intensive phase is extended for 1 more month and the sputum examinations there-after carried out at 4, 6 and 9 months
Category III
Sputum is examined at 2 and 6 months of treatment.
If the result is positive at 2 months, the patient is re-registered and put on Category II treatment.
Any patient treated with Category I or III, who has a positive smear at 5, 6 or 7 months of treatment, should be considered a failure and started on Category II treatment afresh.
