RU2165761C1 - Method for treating the cases of experimental tuberculosis - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves administering 2,4-dioxo-5-fluoropyrimidine (fluorouracyl) at a daily dose of 1-2 mg/kg daily. EFFECT: enhanced effectiveness of treatment. 3 tbl

Description

 The invention relates to medicine, in particular to experimental phthisiology.

 Currently, the main treatment for tuberculosis is chemotherapy, for which a number of basic drugs are used: derivatives of isonicotinic and paraaminosalicylic acids and antibiotics (streptomycin, rifampicin). However, chemotherapy for tuberculosis is complicated by primary and secondary drug resistance of Mycobacterium tuberculosis (MBT) to known drugs. Therefore, there is a constant search for new anti-TB drugs and new methods for treating tuberculosis (RF patents: NN 2008902 A 61 K 31/21, 31/66; 2033159 A 61 K 31/47; 2080114 A 61 K 31/15, 31/295, 31 / 455).

 The most effective and most widely used in the treatment of tuberculosis and experimental tuberculosis is isoniazid - isonicotinic acid hydrazide. Therefore, the prototype adopted a method of treating experimental tuberculosis, including the introduction of an anti-TB drug (M. D. Mashkovsky. Medicines. - M .: Medicine, 1988. - T. 2. - P. 315-316). In this method, isoniazid in doses of 6-15 mg / kg or 0.3-0.9 g per day, usually 10 mg / kg per day, is used as a drug.

 The main disadvantages of the method: the rapid development of resistant to isoniazid forms of MBT, which reduces the effectiveness of treatment, as well as the high toxicity of isoniazid.

 The task of the invention is the provision of effective treatment while expanding the range of drugs used.

 To solve this problem, the authors propose using 2,4-dioxo-5-fluoropyrimidine (fluorouracil) in a daily dose of 1-2 mg / kg daily as a method of treating experimental tuberculosis, including the introduction of an anti-TB drug.

 Fluorouracil belongs to the antimetabolic group of cytostatic agents and is used in the treatment of cancer in daily doses of 10-15 mg / kg in short courses for up to 10 days (M. D. Mashkovsky. Medicines. - M .: Medicine, 1988. - T. 2. - S. 455). The tuberculostatic activity of fluorouracil was discovered by the authors in the "invitro" experiment. It was found that at a concentration of 600 μg / ml or more, fluorouracil inhibits the growth of MBT and is a tuberculostatic agent. However, these data are not sufficient for the use of fluorouracil in the treatment of tuberculosis, since it is not known whether fluorouracil will have the same effect on MBT in a living organism.

 The antituberculous activity of fluorouracil was studied with long-term treatment of experimental tuberculosis in guinea pigs. It was found that fluorouracil in doses of 1-2 mg / kg in terms of anti-tuberculosis action is not inferior to isoniazid and can be used to treat experimental tuberculosis. It is known that anti-TB drugs should be used for a long time (2-3 months or more) due to the long cycle of dividing the office. A study by the authors showed that fluorouracil in a daily dose of 1-2 mg / kg can be used daily for a long time as an anti-TB drug, and this dose does not lead to toxic damage to the body.

 The use of fluorouracil in doses less than 1 mg / kg during treatment leads to results that are less effective than the use of isoniazid. The use of fluorouracil in doses exceeding 2 mg / kg is accompanied by toxic lesions of the animal organism.

The studies were performed on guinea pigs, males and females, weighing 300-400 g. Six groups of animals were formed: 4 experimental to study the effect of fluorouracil, administered daily intramuscularly in doses of 0.5; 1; 2; 2.5 mg / kg; one comparative, receiving daily isoniazid intramuscularly at a dose of 10 mg / kg; and one control, not receiving treatment. Each group consisted of 7 animals. The duration of the experiment was 3 months. The disease was simulated in all animals of all groups by subcutaneous injection of an MBT culture, laboratory strain H37Rv, at a dose of 0.025 mg in a volume of 0.5 ml in the right inguinal region. The control group was left untreated. During the experiment, studies were conducted and the parameters studied:
- histological examination of tissues of the lungs, spleen, liver, intrathoracic and peripheral (infection area) lymph nodes;
- lung lesion index (IPL) - calculated by the ratio of the weight of the lungs to the body weight of the animal;
- the effectiveness index of chemotherapy (IEC) with the studied drugs was calculated according to the formula: 100 - (IPLx100 / IPC), where IPC is the index of lung damage in the control group;
- microbiological examination of homogenates of internal organs for the presence of MBT;
- hemograms - hemoglobin of blood, composition of blood cells;
- the level of serum protein and its fractions.

 The obtained parameters are presented in Table. 1-3, which also includes laboratory data of these indicators.

 From the control group of animals, 3 died during the experiment in the period from 1 to 3 months. The reason is generalized tuberculosis. The index of lung damage in all surviving animals of this group was 0.0243 ± 0.0038 (Table 1). At autopsy, in all cases, multiple tuberculous lesions of the internal organs with numerous foci of caseous necrosis were detected. In all surviving animals, internal office homogenates were seeded. Blood counts in this group of animals compared with the laboratory norm showed a significant decrease in hemoglobin level, a marked increase in granulocytes and a decrease in the number of lymphocytes (Table 2). Proteinograms indicated the development of dysproteinemia due to an increase in globulin fractions b and y (Table 3). All these data indicate the presence of a pronounced specific inflammatory process in animals.

 A comparative group of animals received isoniazid daily in a standard dose of 10 mg / kg intramuscularly (prototype). All animals remained alive during the experiment. When examining the lungs, single subpleurally located foci of lymphoid infiltration were found, in two cases - pneumonic foci. Lymphoid granulomas were found in spleen tissue; small foci of sclerosis were found in intrathoracic and peripheral lymph nodes. In the homogenates of the internal organs by the method of sowing, the growth of MBT was detected. IPL, equal to 0.0111 ± 0.0008, and an IEC of 54%, indicate the effectiveness of isoniazid as an anti-tuberculosis drug for the treatment of experimental tuberculosis.

 In the first experimental group (0.5 mg / kg of fluorouracil), 4 animals died during the experiment. When examining the internal organs, signs of generalized tuberculosis were found, although the degree of damage (the number of tuberculous foci, cases of caseosis) was less pronounced than in animals of the control group. Microbiological examination by the method of sowing internal organs in surviving animals confirmed the presence of MBT. Laboratory studies in this group of animals were not conducted due to the apparent lack of treatment effect.

 The second experimental group of animals received fluorouracil at a dose of 1 mg / kg. All animals survived. When examining the lungs in 3 animals, limited foci of pneumonia were revealed, in other cases, the focuses of lymphoid infiltration. Vast fields of sclerosis were observed in intrathoracic and peripheral lymph nodes, in two cases with foci of caseous necrosis. A few lymphocytic granulomas were found in the spleen, and small foci of cirrhosis were found in the liver. In all cases, an increase in the office of the internal organs was revealed. The value of IPL is approximately half that of the control group and corresponds to the IPL of the comparative group treated with isoniazid (Table 1). The IEH is also at the level of the comparative group. At the same time, blood indices correspond to similar indicators in the comparison group and do not contain signs of toxic damage to the animal’s body with fluorouracil.

 The third experimental group of animals received fluorouracil at a dose of 2 mg / kg. All animals remained alive during the three-month experiment. At autopsy, all small pigs showed single, small, dense lesions in the lungs, in which case histological examination revealed foci of caseosis. Similar changes were found in the spleen, intrathoracic and peripheral lymph nodes. In the liver, in contrast to animals of the second group, foci of cirrhosis were found. Sowing data showed the presence of MBT in the homogenates of the internal organs. IPL and IEC corresponds to these indices in the comparison group treated with isoniazid. The results of a blood test were comparable with the same studies of animals of the second group, which indicates the absence of a pronounced toxic damage to the body by fluorouracil.

 A fourth group of animals received fluorouracil at a dose of 2.5 mg / kg. Four pigs during the experiment died in the period from 5 to 12 weeks. At autopsy, all pigs had single, small, dense foci in the lungs with foci of necrosis and extensive pneumonic foci. In the intrathoracic and peripheral lymph nodes and spleen, foci of sclerosis were found, in the liver - extensive cirrhotic changes. In the homogenates of internal organs, an increase in MBT was detected. Additional studies in this group of animals were not performed due to the severity of nonspecific lesions of the internal organs caused by the toxic effects of fluorouracil.

 The experiments showed that the daily long-term use of fluorouracil in a dose of 1 - 2 mg / kg for the treatment of experimental tuberculosis was effective and has the same anti-tuberculosis effect as isoniazid treatment. The use of a new anti-tuberculosis drug (fluorouracil) increases the effectiveness of treatment for tuberculosis, since the resistance of the office has not yet appeared.

Claims (1)

 A method of treating experimental tuberculosis, comprising administering an anti-tuberculosis drug, characterized in that 2,4-dioxo-5-fluoropyrimidine (fluorouracil) is used as an anti-tuberculosis drug in a daily dose of 1 to 2 mg / kg daily.

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