Tuberculosis Study Guide - M.M. Savula 2002

Care. Treatment
Chemotherapy

The Use of antituberculosis drugs is the cornerstone of treating tuberculosis regardless of its localization. Chemotherapy for tuberculosis patients is administered in hospitals, sanatoriums, and outpatient settings. A feldsher manages Tuberculosis Treatment during the outpatient phase. The treatment regimen is prescribed by a phthisiologist, who specifies in writing the drugs, their single and daily doses, administration schedule (daily, every other day), and duration of therapy. Antituberculosis drugs are classified into three groups:

The first group (the most effective drugs) includes isoniazid, which is prescribed in a daily dose of 5-10 mg/kg orally after meals (the adult dose is 0.3-0.6 g) once daily, or less frequently, in two divided doses. Isoniazid is also available in ampoules as a 10% solution of 5 ml for intramuscular or intravenous administration. Analogs of isoniazid include phthivazide (20-30 mg/kg or 1.0-1.5 g per day for adults) and metazide (20-30 mg/kg, but not exceeding 1 g per day). The second drug in the first group is the antibiotic rifampicin, which is prescribed at a dose of 8-10 mg/kg (0.45-0.6 g per single dose) orally, before meals. Rifampicin is also available in ampoules for intravenous administration.

The second group consists of moderately active drugs. These include the Antibiotics streptomycin, kanamycin, and florimycin, which are prescribed to adults at 1 g intramuscularly (15-20 mg/kg) once daily. Streptomycin and kanamycin are also used for inhalation, instillation into the pleural and peritoneal cavities, and intra-articular administration. Ethambutol is taken orally at 20-25 mg/kg (0.8-1.6 g per day for adults) as a single dose after meals. Pyrazinamide (tizamide) is prescribed at 20-30 mg/kg (for adults, 1.5-2.0 g in a single dose or 2-3 divided doses) after meals. Ethionamide or its analog protionamide is taken at 10-20 mg/kg (for adults, 0.25 g three times a day) after meals.

The third group (the least effective drugs) includes sodium para-aminosalicylate (PAS), which is prescribed at 150-200 mg/kg (or 9-12 g per day in a single dose or 2-3 divided doses) orally, after meals, and thioacetazone (tibone), administered at 2-2.5 mg/kg (0.05 g three times a day for adults) after meals. These two drugs have recently been rarely used. A soluble form of thioacetazone, solutizone, available in 2 ml ampoules of a 2% solution, is used for inhalation or intrabronchial administration.

Recently, fluoroquinolones (ofloxacin, ciprofloxacin), clarithromycin, amikacin, rifabutin (a derivative of rifampicin), and flurenizide, which has high bacteriostatic activity and low toxicity, have been used in the Treatment of tuberculosis (especially chronic forms where resistance to classic chemotherapy drugs develops).

During the initial inpatient phase of treatment, chemotherapy for patients is managed by phthisiologists, guided by specific principles.

♦ A combination of several antituberculosis drugs is always prescribed.

♦ In the initial phase (2-3 months), 3-4 tuberculostatic drugs are used (most commonly isoniazid, rifampicin, pyrazinamide, streptomycin, or ethambutol); In the second phase, 2-3 drugs are administered in single daily doses. During the second phase, antituberculosis drugs may be taken 3 times a week.

♦ The total duration of treatment is 6-18 months.

♦ When selecting chemotherapy drugs, patient tolerance and mycobacterial susceptibility must be taken into account.

Tuberculosis chemotherapy regimens recommended by the WHO for the treatment of various patient groups are presented in Table 1.

Class="center">Table 1 Standardized tuberculosis chemotherapy regimens recommended by the WHO

Treatment of tuberculosis patients is carried out under the strict supervision of healthcare professionals.

During the outpatient phase, the optimal form of monitoring is the administration of tuberculostatic drugs at a TB dispensary, a TB cabinet, an occupational health clinic, or a feldsher-midwife station (FAP) in the presence of a healthcare worker. Such monitoring is most easily achieved with a single daily dose of drugs on an intermittent schedule (every other day or twice a week). If the patient takes antituberculosis drugs at home, they are dispensed for no more than 5-7 days. It must be explained to the patient that antituberculosis drugs should be stored in a dark place out of reach of children. The feldsher can assess the regularity of drug intake by counting the remaining tablets or capsules on a given treatment day. Drug adherence can also be monitored using special qualitative urine tests performed at the TB dispensary. The feldsher records the administration of antituberculosis drugs in the treatment sheet (date, drug, dose), which is pasted into the outpatient medical record after the treatment course is completed.

During the treatment period, the feldsher monitors the patient's condition and tolerance to antituberculosis drugs. Therefore, it is essential to be aware of the main manifestations of their side effects.

Most antituberculosis drugs can cause allergic side effects. They occur most frequently during treatment with streptomycin, kanamycin, and florimycin, and less commonly with isoniazid or other drugs. Manifestations include Skin itching, rash, Conjunctivitis, rhinitis, joint pain, and fever. If these symptoms occur, the drug must be discontinued, and desensitizing agents (diphenhydramine, suprastin, calcium gluconate) should be administered. Anaphylactic Shock may develop, requiring emergency care. Rifampicin occasionally causes serious allergic complications accompanied by fever, joint pain, hemolysis of red Blood Cells, and The Development of ACUTE RENAL FAILURE. After administering desensitizing agents and prednisolone, such patients must be immediately transported to a specialized hospital.

Toxic reactions have specific characteristics for each drug. Under METABOLISM/18.html">The Influence of isoniazid or phthivazide, headache, insomnia or drowsiness, impaired skin sensitivity of the limbs, paresthesia (a crawling sensation), and chest pain in The Heart area sometimes occur. Prescribing Vitamins B₁ and B₆ can prevent these disorders. Therefore, along with antituberculosis drugs, which almost always include isoniazid, courses of vitamins B₁ and B₆ are prescribed.

Streptomycin, kanamycin, and florimycin sometimes cause Hearing loss, balance disorders, dizziness, and, rarely, toxic Kidney damage. To prevent the Toxic effects of these drugs, calcium pantothenate and B vitamins are prescribed alongside them. Patient Complaints of hearing loss are grounds for discontinuing these drugs.

Under the influence of ethambutol, visual impairment and Color Vision disturbances may occur, which should serve as a signal to discontinue the drug. For this reason, ethambutol is not prescribed to young children whose visual function cannot be monitored. Sometimes ethambutol causes dizziness and dyspeptic symptoms. To prevent toxic effects, vitamin B₁ and ATP are administered concurrently.

Ethionamide or protionamide sometimes causes loss of appetite, nausea, vomiting, and diarrhea. To prevent this, vicalin, nicotinamide, or nicotinic acid is prescribed.

Pyrazinamide sometimes causes dyspeptic disorders and, with long-term treatment, joint pain. To avoid the side effects of pyrazinamide, vitamins B₆, B₁₂, and nicotinamide are prescribed concurrently.

While taking PAS, loss of appetite, nausea, vomiting, diarrhea, or constipation may be observed. The drug is better tolerated when taken with milk.

Most antituberculosis drugs, especially when used in combination, can cause toxic Liver damage. This is more likely to occur in individuals who consume alcohol during chemotherapy or those with a history of liver disease. Symptoms include loss of appetite, nausea, vomiting, and sometimes pain in the right hypochondrium, followed by the development of jaundice. Treatment should be discontinued, and a diet along with hepatoprotectors should be prescribed.

In all cases, if side effects to antituberculosis drugs occur, treatment must be suspended, as its continuation may lead to serious complications. The patient must be referred to a phthisiologist for a consultation to decide on the possibility of continuing and adjusting the therapy.