Clinical and Biological Investigations on the New Antituberculosis Drugs (Pyrazinamide and Cycloserine)

¹ Director, Carlo Forlanini Institute.
² Assistants at the Carlo Forlanini Institute.

1. A series of clinical and biological investigations on pyrazinamide and cycloserine in the treatment of pulmonary tuberculosis are reported.

These investigations were accompanied by the following laboratory studies: serum electrophoresis, phagocytic index, precipitable bound iodine, adrenal cortical function, behavior of specific proteases of defense in urine, plasma lipasic power, serum cholesterol, serum bilirubin, plasma fibrinogen, prothrombin time, and finally with the serolability tests and the charge tests of liver function.

Pyrazinamide showed a favorable action on tuberculous lesions in a limited number of cases and for a short duration, not exceeding 35-40 days of therapy, following which toxic phenomena were observed, predominantly hepatic. The laboratory tests in this subsequent period of study showed increasing variance from normal values, with an increase of the precipitable bound iodine and a dissociation between the globulin with an increase in the beta and a decrease in the gamma fraction.

2. Cycloserine, on the basis of our studies, was thought to be a more patient antibiotic, manifested by definite improvement in the x-rays of both fresh exudative cases, as well as in cases of chronic cavitary disease, some of these being resistant to the usual therapeutic measures, with appreciable regression of the far advanced cavitations, and conversion of a positive sputum to negative in both types of cases. Its toxic action on the central nervous system is not frequent and does not usually interfere with the continuance of therapy. The laboratory tests have generally shown normal values even after the second and third month of therapy with the precipitable protein bound iodine, serum proteins, and particularly beta gamma globulin, plasma fibrinogen, prothrombin time, plasma lipasic power, specific proteases of defense in urine, and the charge tests for liver function, presenting a behavior opposite to that of pyrazinamide.