Comparison of the Pharmacokinetics of a child-friendly Fixed-Dose Combination of rifampin and isoniazid and separate tablets in children with pulmonary tuberculosis

<b>Introduction:</b> First-line anti-tuberculosis drugs:isoniazid(H),rifampicin(R),pyrazinamide(Z),ethambutol(E) are used for tuberculosis with confirmed or suspected drug susceptibility of the pathogen. These drugs may be more convenient to use in combination with fixed doses(FDC), especially in childhood. The effectiveness of chemotherapy is influenced by many factors,including the bioavailability of the drugs. <b>Aims and objectives:</b> Our aims and objectives were to study is to study the features&nbsp;of the pharmacokinetics(PK)of rifampicin and isoniazid in the separate tablets(ST) and in the composition of FDC(H 150mg+Z 375mg+R 150mg). <b>Methods:</b> The study included 22 patients with new respiratory tuberculosis. Patients were conditionally divided into the main (FDC treatment) and control(ST treatment) groups. Patient arms were comparable by gender, age, clinical, radiological and laboratory. In I&nbsp;group (n=11,average age 6,3±2,6) 3-FDC dispersible tablets in combination with E daily for 2-3 months and in II group (n=11,average age 7,0±3,1) ST of H, R, Z and&nbsp;E&nbsp;for 2-3 months were taking into account age-related dosages. Venous blood sampling (4 ml) for PK&nbsp;evaluation, blood samples were collected at pre-dose and 2,4,24 hours after taken the drugs. <b>Results:</b> <b>Conclusion:</b> Pharmacokinetic parameters of R and H in ST and FDC(H 150mg+Z 375mg+R 150mg)are not statistically significant.