FACTORS AFFECTING PENETRABILITY OF CHEMOTHERAPEUTICS INTO THE LESION
Presumption from Peroxidase Reaction of Isoniazid-Resistant Tubercle Bacilli
1978 Volume 26 Issue 2 Pages 216-220
Details
1978 Volume 26 Issue 2 Pages 216-220
From the mode of peroxidase reaction of tubercle bacilli in sputum specimens of the patients with pulmonary tuberculosis having been administered isoniazid, an attempt to presume the penetrability of isoniazid into the lesion was made. In case that the initial concentration of isoniazid in the growth environment of tubercle bacilli is very low, even if the bacilli become resistant to isoniazid, peroxidase reaction of the bacilli hardly becomes negative. This phenomenon utilized in this study.
The number of cases in which bacilli resistant to no less than 0. 3 Pg/ml of isoniazid were negative to peroxidase reaction was 11, and in 10 cases out of them, the period from the onset of the disease to the beginning of isoniazid administration was less than 12 months. Among them, all of which roentgenologic type of lesion at the beginning of isoniazid administration was known were infiltrating-caseous type, without cavity or having cavity with non-sclerotic wall.
The number of cases in which bacilli resistant to not less than 0.3μg/ml of isoniazid showed positive peroxidase reaction was 15, and in 10 cases out of them, the period from the onset of the disease to the beginning of isoniazid administration was more than 12 months. And the cases in which roentgenological type of lesion at the beginning of isoniazid administration was known were, except one case, all fibrocaseous type, without cavity or having cavity with sclerotic wall.
In spite of the fact that the period from the onset of the disease to the beginning of isoniazid administration was less than 12 months, in 3 cases out of 5 cases of which peroxidase reaction was positive, the blood level of biologically active isoniazid was low.
Therefore, in case that the modes and doses of administration of isoniazid were kept same, it is thought that the most important factor affecting the penetrability of isoniazid into the lesion lies in whether the lesion is new or old, and the rate of inactivation of isoniazid could also be a factor.
