Research based on a study commissioned by the World Health Organisation (WHO), and published online in the Open Access journal PLoS Medicine, has clearly vindicated India’s position on treating newly diagnosed TB patients.
“The papers clearly endorse the stand taken by RNTCP [Revised National Tuberculosis Control Programme],” said Dr. V. Kumaraswami, Director-in-Charge of the Tuberculosis Research Centre, Chennai.
India has been facing much criticism for treating patients for six months using a different regimen where drugs are given only thrice a week and not daily as most developed countries do. Considering the huge disease burden in India, the intermittent treatment was suspected to cause drug resistance. China is the only other country that follows the same regimen as India.
Why India opted for the intermittent therapy
There are several reasons why India chose the thrice-a-week regimen. “It is convenient, reduces cost by more than half, and lowers adverse drug reactions when given intermittently,” said Dr. Kumaraswami. “It also enables the implementation of DOTS.”
The WHO study, which reviewed 57 randomised controlled trials involving 21,000 patients, found that: “There was little evidence of difference in failure or relapse with daily or intermittent schedules of treatment administration.”
The study was undertaken to provide WHO the much needed evidence for a revision of TB treatment guidelines.
Different drug regimen
One of the papers looks at newly diagnosed patients undergoing treatment for the first time. The four antibiotics used for treating such patients are rifampicin, isoniazid, ethambutol and pyrazinamide.
According to WHO’s treatment guidelines, patients can be treated by either a six-month or an eight-month regimen.
In the case of the eight-month regimen, all four antibiotics are given for the first two months, and two drugs for the remaining six months. Rifampicin is not one of the drugs given during the remaining six months. This was the option given to resource-poor countries and where the Daily Observed Treatment, Short-course, (DOTS) implementation was difficult.
In the case of the six-month regimen, all four drugs are administered for the first two months, and rifampicin and another antibiotic for the remaining four months. The medicines can be given either daily or thrice a week (intermittent dosing schedule) during the entire course of the therapy.
India and China are the only two countries that have opted for a thrice-a-week dosage during the six-month regimen. Most developed countries have gone in for the daily regimen.
Duration of rifampicin treatment
There were two choices given by WHO for using rifampicin. Countries could either use it throughout the six-month therapy or go for the eight-month therapy where rifampicin is given daily only during the first two months and stopped thereafter.
The research paper found that there was increased risk of poor treatment outcomes and drug resistance when rifampicin was not given throughout the six-month therapy period and when it was given only during the first two months in the case of the eight-month regimen.
Time to revisit the guidelines
According to the paper, WHO had changed the treatment guidelines from six months to eight months for the 24 high-incidence countries for newly diagnosed untreated patients. But the evidence from the study clearly indicates that the change was not required. “WHO will [now] recommend only the six-month (rifampicin throughout) regimen, and the eight-month regimen will no longer be recommended,” the paper states.