Chromosome analyses in man in the course of chemoprophylaxis against tuberculosis and of antituberculosis chemotherapy with isoniazid.

Cytogenetic analyses were carried out in lymphocytes of 37 persons before and during a primary chemoprophylaxis or a preventive chemotherapy with isoniazid as well as of 30 patients suffering from active pulmonary tuberculosis before and during a chemotherapy with isoniazid in combination with two other antimycobacterial drugs. The results of the four participating research groups consistently reveal no indication for a chromosome damaging activity of isoniazid, of its metabolites in the human organism and of the administered drug regimens.