Tuberculosis

EACS 2015: 3-Month Isoniazid/Pyrazinamide Regimen Prevents TB in People with HIV

A daily 3-month regimen of isoniazid and pyrazinamide is just as effective at preventing the development of active tuberculosis (TB) in people living with HIV as a 6-month course of isoniazid alone, according to findings from a Russian study presented by Zinaida Zagdyn at the 15th European AIDS Conference last week in Barcelona.

[Produced in collaboration with Aidsmap.com]

Isoniazid has been shown to prevent the development of active TB in people with HIV in sub-Saharan Africa who tested positive for TB exposure. However, the 6-month course of treatment may be difficult for people to adhere to, and there is interest in reducing the length of the preventive treatment regimen. A 3-month course of isoniazid and pyrazinamide is already recommended as an option for TB prevention in Russian guidelines, but clinical trial evidence regarding its efficacy and safety is lacking.

The incidence of TB in people living with HIV in Eastern Europe is very high, and another study presented at the conference showed that HIV-positive people in the region were 4 times more likely to die after being diagnosed with TB than people in Latin America or Western Europe, despite receiving a similar course of treatment. Reducing the risk of developing TB is a priority for improving the health of people living with HIV in Eastern Europe.

The St Petersburg TB Research Institute and the Leningrad Regional AIDS Center conducted a randomized clinical trial that included 514 consecutive patients recruited from May 2009 through May 2011. Patients were randomized by day of diagnosis, so that 216 people were assigned to receive a 3-month regimen of isoniazid and pyrazinamide, while 298 were assigned to receive a 6-month regimen of isoniazid alone.

Participants were followed for 2 years after completion of preventive treatment to assess the primary study outcomes of development of active TB or death.

Approximately two-thirds of study participants were men (6%), 70% had been exposed to HIV through injection drug use, and 90% were receiving antiretroviral therapy at the time of TB diagnosis. 80% of study participants were coinfected with viral hepatitis.

The findings showed that 70.0% of patients in the short-course group and 74.5% of those in the 6-month isoniazid group completed the treatment course, with approximately half of non-completers in each group lost to follow-up before the completion of treatment.

After a mean follow-up period of 28.5 months, there was no significant difference in the incidence of active TB -- 2.7% in the isoniazid group vs 4.8% in the short-course group -- although a trend was evident favoring the short-course group in deaths from TB (1.4% vs 0%).

There was no significant difference in adverse events (chiefly liver totoxicity), which occurred in 13.0% of people receiving short-course therapy and 12.1% of people receiving isoniazid.

10/28/15

Reference

Z Zagdyn, A Kovelenov, A Beltyukov, et al. A Short-course isoniazid and pyrazinamide compared with 6-month isoniazid for tuberculosis prevention in HIV-infected adults: The Russian Randomized Clinical Trial.15th European AIDS Conference. Barcelona, October 21-24, 2015.Abstract PS2/3.