[Preventive chemotherapy for tuberculous infection. Arguments against]

Preventive chemotherapy with isoniazid (INH) is generally considered to be indicated in some patients with tuberculous infection who have a high risk of evolution towards disease. There are, however, some practical problems of treatment which may limit its application: correct assessment of tuberculin tests and risk factors, monitoring of treatment, patient compliance and management of possible side effects. Current treatment may not yet represent the ideal solution.