Products
Phthisoactiv
Pharmacotherapeutic group
Antituberculosis drugInternational name
Isoniazid + PyridoxineDosage form
TabletsPhthizoactiv is a combination drug comprising isoniazid, an anti-TB agent, and pyridoxine (vitamin B6).
Pharmacodynamics
Isoniazid shows a bactericidal effect against actively replicating Mycobacterium tuberculosis. It exerts its action by inhibiting synthesis of mycolic acids, a component of Mycobacterium cell wall. The minimum inhibitory concentration (MIC) of isoniazid against Mycobacterium tuberculosis is 0.025-0.05 mg/L. It has a moderate activity against slow- and rapid-growing atypical mycobacteria.
Pyridoxine (vitamin B6). It is involved in metabolism and is essential for the normal function of the central and peripheral nervous system. TB-infection results in pyridoxine deficiencies. So, the daily dose of this vitamin increases up to 60 mg. There are no pharmacokinetically or microbiologically relevant drug-drug interactions when pyridoxine is co-administered with isoniazid, lomefloxacin, pyrazinamide, and ethambutol. Pyridoxine reduces neurotoxicity induced by anti-TB drugs.