Severely ill patients with tuberculosis: the option to reduce mortality and optimize management with the help of step therapy and the usage of infusion forms of anti-tuberculosis drugs
Authors: Lytvynenko N.A. 
Published: July 2021

Background. A doctor often has to answer the question whether it is sufficient to treat tuberculosis (TB) exclusively with the oral forms of anti-tuberculosis drugs (ATD). In general, the answer is yes, if the absorption of drugs and their delivery to the affected organs is not impaired. However, drug absorption is often impaired due to hypoalbuminemia, TB of the gastrointestinal tract or central nervous system, concomitant diseases of the digestive system, alcoholism, hyperthyroidism, diabetes, or in the elderly patients.
Objective. To evaluate the feasibility of using infusion forms of ATD.
Materials and methods. Review of current guidelines.
Results and discussion. The advantages of exclusively oral administration of ATD include convenience, low cost, the possibility of usage in an outpatient setting, whereas the main disadvantage is that it is not always possible to create the required concentration of ATD in blood plasma. In turn, the advantages of intravenous ATD include the creation of maximal concentrations in blood plasma and foci of infection, fewer side effects in the digestive system, patients’ awareness of the importance of treatment, whereas disadvantages are high cost and low adherence to treatment. The use of part of the ATD as a step therapy (course of intravenous infusions with subsequent transition to oral administration) allows to create the maximal concentration of active substances in blood plasma and affected organs at the beginning of treatment, to provide better cost/effectiveness ratio in comparison to previously listed regimens, and to increase the treatment adherence without compromising the quality of life of patients. The additional cost of intravenous ATD delivery devices is the main disadvantage. Criteria for the transition from the infusions to oral administration are the elimination of bacterial excretion, obtaining a stable positive dynamics of the clinical condition, elimination of the causes of the need for intravenous treatment (normalization of swallowing function, elimination of malabsorption). Indications for step therapy include the severe forms of TB, severe disorders of the central nervous system and gastrointestinal tract, the presence of severe comorbidities, pre- and postoperative periods, mental disorders, side effects of 3rd-4th degree in case of oral ATD intake. The duration of the infusion course is determined individually, but in average it is about 1-2 months. Such drugs as rifampicin, isoniazid, ethambutol, levofloxacin, moxifloxacin, linezolid, and carbapenems exist in the infusion form.
Conclusions. 1. Infusion of ATD as a part of step therapy can improve the quality of treatment of TB patients. 2. Criteria for the transition from infusions to oral administration are the elimination of bacterial excretion, obtaining a stable positive dynamics of the clinical condition, elimination of the causes of the need for intravenous treatment. 3. The duration of the infusion course is determined individually (in average – 1-2 months).