STUDIES ON THE ANTITUBERCULOUS ACTIVITY OF ALPHA-ETHYL-THIOISONICOTINAMIDE-METHANESULFONATE AND ITS SIDE EFFECTS

Abstract

Observations were presented on the activity in vitro and in vivo of alpha-ethyl-thioisonicotinamide-methanesulfonate (Th-S). This compound is a water-soluble substance. The molecular weight of Th-S is 262.3,1.6 times that of 1314Th (166.2). 1. The minimum inhibitory concentration (MIC) of Th-S against H37Rv strain in Kirchner's liquid medium with 10 per cent bovine serum, proved to be 1.25γ per ml. 2. The toxicity of Th-S in mice was tested, and LD50 was found to be 1240mg. per kg. when the compound was administered orally, 1000mg. per kg. when injected subcutaneously, and 500mg. per kg. by intravenous injection. 3. Mice infected with tubercle bacilli of human origin (Kurono strain) were employed. In this experiment, the therapeutic effect of Th-S showed the same good therapeutic effect of 1314Th. 4. The tuberculostatic activity of the serum when Th-S was given orally was recognized up to 2 to 4 hours after administration, and this tuberclostatic activity seemed to appar earlier than that of 1314Th enteric-coated tablet given orally. 5. The writers attempted intravenous drip of Th-S to patients poorly tolerating 1314Th. The side effects were still fairly often. Divided oral administration of Th-S was better tolerated than that of 1314Th by these patients.