Antimicrobial therapy of pulmonary tuberculosis.

The discovery, some nine years ago, of the highly specific antituberculous drug, isoniazid, marked an important advance in the antimicrobial therapy of tuberculosis, first practised successfully with streptomycin and p-aminosalicylic acid (PAS) in the late 'forties. Isoniazid is relatively non-toxic and, unlike streptomycin, can be administered orally, so that it is eminently suitable for use, either alone or in combination with PAS, in the domiciliary treatment of tuberculous patients. The wisdom of employing it on a large scale in home-treatment programmes, however, has been questioned on the ground that such wide-spread use might result in a spread of tubercle bacilli resistant to the drug. This controversial subject is discussed in some detail in this general review of the chemotherapy of tuberculosis. The author is convinced that, so far, the benefits of isoniazid therapy have outweighed the disadvantages and, though well aware of the possible consequences in terms of isoniazid-resistance, sees no reason at the present time for not making full use of this valuable weapon in the antituberculosis armamentarium.