Approaches to clinical research.

The effi cacy of the sulfones in the trea tment of leprosy was proven in a controll ed study by Doull et al. (5), but, because it takes several years to arrest the disease in a case of leprosy and make it bacteriologically negative, search for more effective drugs has continued to the present time. Several drugs found effective in human leprosy have been evaluated by Doull (5) and Doull et aT. (G. 7) in controlled studies. Only dihydrostreptomycin was found equal to the sulfones, and it was not superior. Para-aminosalicylic acid, isoniazid, Ciba 1906, cycloserine, and pyrazinamide were all found less effective than DDS as antileprosy drugs. The sulfones were originally proven ineffective in human tuberculosis, but later found effective in leprosy. Perhaps many similar drugs are active against acid-fast infections in vitro and in laboratory animals, and should be tri ed and evaluated in leprosy also. The literature furnishes records of several drugs that have been tried in human leprosy in uncontrolled pilot studies. Those who tried them recommend more intensive trials in a larger number of patients and for longer periods of observation.