Latent tuberculosis in childhood: tolerability of two different therapeutic approaches

Isoniazid monotherapy for six or nine months and the combination of isoniazid and rifampicin for three or four months are the most used regimens for treating latent tuberculosis. The main aim of this retrospective study is to evaluate the safety of latent tuberculosis treatment by analysing side effects in both regimens.

Children with latent tuberculosis and treated with isoniazid or isoniazid and rifampicin were included. Periodic evaluations with clinical assessment and blood exams were carried out to detect any adverse reaction, including elevated serum transaminases.

441 children were included, 14.5% treated with isoniazid and 85.5% with isoniazid and rifampicin. Five patients under combined treatment developed hepatotoxicity within the first month. None of the patients under isoniazid monotherapy presented hepatotoxicity. A slight increase of transaminases level was found in both groups (18.7% in isoniazid and 10.3% in isoniazid/rifampicin groups, respectively) without causing discontinuation of treatment, with values normalization at the subsequent checks.

Both regimens resulted safe. Hepatotoxicity occurred rarely and within the first month. For this reason, it may be appropriate to perform liver function tests after about one month from the beginning of therapy to avoid diagnostic delays.