Chemotherapy of pulmonary tuberculosis.

Many attempts have been made in the past to find chemotherapeutic agents active against the tubercle bacillus, and some agents alleged to have had such action, notably gold compounds, have had a considerable vogue. The discovery of the antibacterial action of the sulphonamides stimulated a search for compounds of related constitution having an action against the tubercle bacillus, and this resulted in the investigation of the effects of the various sulphone compounds. The therapeutic activity of these compounds, however, was so slight, especially in relation to their rather severe toxic effects, that it is doubtful whether, even had no more active agent been discovered, they would ever have entered into general use. It was with the discovery of streptomycin that the first really effective and practicable antibacterial therapy of tuberculosis became available. No other agent comparable with streptomycin as a clinically useful antibacterial agent in tuberculosis has been discovered. Para-aminosalicylic acid (PAS) has an undoubted, but less potent, antibacterial effect, and has found its principal place as an adjuvant to streptomycin. The thiosemicarbazones appear to be about as active as PAS against the tubercle bacillus, but their effectiveness as an adjuvant to streptomycin has not yet been fully explored; they certainly have more serious toxic effects than PAS.