The activity of the antituberculous drugs as the activity of the other antibacterial drugs can be assessed in the test tube, in the laboratory animal and in man. All together the results of these assessments give a relatively clear view of the mechanisms of action of the different antituberculosis drugs against all bacillary populations. The minimal inhibitory concentration (MIC) of each antituberculous drug can be adequately measured in a liquid medium with either bovine serum or bovine albumin that permits good growth of Mycobacterium tuberculosis and that contains no components as tween 80 that increase artificially the antibacterial activity of the drugs. Using such a medium isoniazid ranks first with the lowest MIC, followed by rifampicin, streptomycin, ethambutol and pyrazinamide. It should be emphasized that pyrazinamide has no activity at all when tested as the other drugs at a neutral pH and is active only at an acid pH. Another way to assess comparatively the antituberculous drugs is to study the ratio of the blood levels obtained in man on the MICs. Three drugs, namely isoniazid, rifampicin and streptomycin have extremely favourable ratios of the blood levels on the MICs. It can therefore be predicted that these three drugs will have the best bactericidal activity against tubercle bacillus in the test tube.
|Original language||English (US)|
|Number of pages||8|
|Journal||Revista de Igiena Bacteriologie Virusologie Parazitologie Epidemiologie Pneumoftiziologie - Series Pneumoftiziologie|
|State||Published - Dec 1 1985|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine