Anti TB Drugs By Dkookihhihohohhrwa.pptx

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1. Anti-tubercular agents

2. Anti-tubercular agents are medications used to treat tuberculosis (TB), a bacterial infection primarily affecting the lungs. These agents work by targeting the bacteria responsible for TB, primarily Mycobacterium tuberculosis. These agents work by targeting different stages of the bacterial life cycle or by interfering with essential bacterial processes.

3. Chemical Classification: Isonicotinic acid hydrazide derivative: Example Isoniazid (INH ) :

4. Isoniazid (INH) : Mechanism of Action (MOA) : Isoniazid inhibits the synthesis of mycolic acids, which are essential components of the mycobacterial cell wall. It specifically targets the enzyme enoyl-acyl carrier protein reductase ( InhA ), which is involved in mycolic acid synthesis. Without mycolic acids, the bacterial cell wall becomes destabilized, leading to cell lysis and death.

5. Rifampin (RIF) : Mechanism of Action (MOA) : Rifampin inhibits bacterial RNA synthesis by binding to the beta subunit of bacterial DNA-dependent RNA polymerase, thus blocking the transcription of bacterial RNA. This prevents the synthesis of essential proteins and ultimately leads to bacterial death.

6. Ethambutol : Mechanism of Action (MOA) : Ethambutol inhibits the synthesis of arabinogalactan , an essential component of the mycobacterial cell wall. It specifically targets the enzyme arabinosyl transferase , which is involved in the synthesis of arabinogalactan . By disrupting cell wall synthesis, ethambutol impairs bacterial growth and replication.

7. Pyrazinamide (PZA) : Mechanism of Action (MOA) : The exact mechanism of action of pyrazinamide is not fully understood. However, it is believed to be converted into pyrazinoic acid by the bacterial enzyme pyrazinamidase . Pyrazinoic acid disrupts the membrane potential of Mycobacterium tuberculosis, leading to inhibition of cellular metabolism and ultimately bacterial death.

8. Aminoglycosides (e.g., Streptomycin, Amikacin ) : Mechanism of Action (MOA) : Aminoglycosides bind to the bacterial ribosome and inhibit protein synthesis by causing misreading of mRNA or by blocking the initiation of protein synthesis. This ultimately leads to the accumulation of defective proteins and cell death.

9. Ethionamide : MOA : Ethionamide is an antibiotic used primarily in the treatment of tuberculosis (TB). It works by inhibiting the enzyme mycobacterial fatty acid synthase (FAS-II), which is essential for the synthesis of mycolic acids, a key component of the mycobacterial cell wall. By disrupting the synthesis of mycolic acids, ethionamide interferes with the integrity of the mycobacterial cell wall, ultimately leading to cell death.

10. Aminosalicylic Acid (PAS) : MOA : Aminosalicylic acid, also known as PAS, is another antibiotic used in the treatment of tuberculosis. Its exact mechanism of action is not fully understood, but it is believed to interfere with bacterial folic acid synthesis. Folic acid is essential for the synthesis of nucleic acids (DNA and RNA) in bacteria. By inhibiting folic acid synthesis, PAS disrupts bacterial growth and replication, ultimately leading to cell death.

11. rifampin

12. Inhibition of Cell Wall Synthesis : Cycloserine works by inhibiting enzymes involved in the synthesis of peptidoglycan , an essential component of bacterial cell walls. Peptidoglycan provides structural support and protection to bacterial cells. By disrupting its synthesis, cycloserine weakens the cell wall, making the bacteria more susceptible to damage and death . Targeting D- Alanine : Cycloserine specifically inhibits two enzymes involved in the biosynthesis of peptidoglycan , namely alanine racemase and D- alanine ligase . These enzymes are responsible for converting L- alanine to D- alanine , an essential component of the peptidoglycan structure. By inhibiting these enzymes, cycloserine disrupts the formation of D- alanine , which is crucial for cross-linking the peptidoglycan chains in the bacterial cell wall.