SM, INH, PASの臨床耐性限界

概要

論文の詳細を見る
To decide the clinical significance of the critical drug resistance concentration, studies were done from two aspects. One was an approach from the distribution of naturally resistant variant of the wild strains and another was the one from the clinical view point. The technique used was the proportion method of Canetti, using 1% Ogawa medium with cork stop. Proportion of resistant variants to SM, INH and PAS was measured on strains isolated from previously untreated patients. Considering the variation of the proportion between cases in each drug concentration the, variation of the same strain measured at different days or lots (Table 1), and the decreasing trend of the median value of colonies shown in Fig., it seemed reasonable to take 4mcg of SM, 0.1mcg of INH and O.5mcg of PAS as critical concentrations. For clinical investigation, the grade of drug resistance was divided into 4 categories; that is, sensitive, criteria 1, 2 and 3 as presented in Table 2. A study was done on cases treated for more than 6 months with 3 major primary drugs and have only one drug resistance of each criteria. Minimal cases were excluded from this study as all of them converted to negative regardless of resistance (Table 3). According to this study, the treatment failure was found in 0.4% of the sensitive, and 8.3% in criteria 3 among the original treatment group but there was no statistically significant difference, while among the retreatment group, significant difference was found between sensi tive and criteria 2 (Table 6). Accordingly, it seemed to be reasonable to take criteria 2 as a critical concentration from clinical stand points. Concerning bacillary relapse, temporally or permanent (Table 7), there was a significant difference between sensitive and criteria 3 of the original treatment group and between sensitive and criteria 1 of the retreatment group. The relation between the period of chemotherapy and resistance was examined from the previous history taken at the time of hospitalization. The number of drug resistant cases according to criteria 3 was too few in number among cases after one year or more treatment with SM, INH and PAS, alone or combinated and resulted in failure (Table 8). Similarily, many of hospitalized cases did not become resistant according to criteria 3 in spite of unsuc cessful treatment (Table 9). Considering all these facts, we concluded that the clinically significant critical drug resist ance concentration by using 1% Ogawa medium with cork stop is one percent or more of the following drug concentration ; 10mcg of SM, 0.2mcg of INH, and 1mcg of PAS. But it is also recommendable to take 4mcg of SM, 0.1mcg of INH and 0.5mcg of PAS as subcritical concentrations.
日本結核病学会の論文

SM, INH, PASの臨床耐性限界

スポンサーリンク

概要

著者

関連論文

スポンサーリンク