The January issue of Chest published the results of a study by scientists at the University of East Carolina, which showed that the appointment of a combination of pyrazinamide and of rifampicin for the treatment of latent tuberculosis is accompanied by a more pronounced hepatotoxicity, but also of a higher effectiveness compared to monotherapy with isoniazid.

The main objective of prescribing anti-tuberculosis drugs in patients with latent tuberculosis is to prevent the activation of the tuberculosis process. According to current recommendations, patients with a latent form of tuberculosis and a high probability of reactivation of the process should follow a 9-month course of isoniazid monotherapy.

In clinical studies, it has been shown that in patients infected with HIV and a latent form of tuberculosis, the use of a combination of pyrazinamide and rifampicin for 2 months is a very effective method for preventing reactivation. of the tuberculosis process and has similar hepatotoxicity compared to isoniazid monotherapy. However, cases of extensive liver damage during combination therapy have been noted.

To assess the efficacy and safety of these regimens in clinical practice, Dr. McNeill and his colleagues examined 224 patients with latent tuberculosis who were treated with a combination of pyrazinamide and rifampicin daily for 2 months, or isoniazid monotherapy for 6 months.

Complete treatment was completed in 71% of patients receiving combination therapy and 59% in the isoniazid monotherapy group. Signs of hepatotoxicity were noted in 13% of cases in the combination therapy group with pyrazinamide and rifampicin, and in 4% of cases in the isoniazid group. In a subsequent evaluation, manifestations of hepatotoxicity were considered serious in 5% of patients treated with a combination of pyrazinamide and rifampicin. However, after the implementation of procedures to closely monitor the activity of liver enzymes, none of the remaining 67 patients receiving combination therapy experienced severe hepatotoxic reactions.

Thus, the appointment of a combination of pyrazinamide and rifampicin for 2 months can be recommended for the treatment of latent tuberculosis, provided that the activity of hepatic enzymes is closely monitored. This treatment regimen is particularly preferred when there is doubt about patient compliance, since it allows complete treatment to be completed in a larger number of patients than when using isoniazid monotherapy regimens from 6 to 9 months.