Paper II
2025 August (Supplementary) (2010 Scheme)

Question

Classify drugs used in the treatment of Tuberculosis. Outline the mechanism of action, adverse effects and uses of Rifampicin. (2+4)

Q16 marksEssays

Answer

Classification of antitubercular drugs

LineDrugs
First-lineIsoniazid, Rifampicin, Pyrazinamide, Ethambutol, Streptomycin
Second-lineFluoroquinolones, Aminoglycosides (Kanamycin, Amikacin), Ethionamide, Cycloserine, PAS, Bedaquiline, Linezolid

Rifampicin — mechanism, adverse effects, uses

  • Mechanism: rifampicininhibits bacterial DNA-dependent RNA polymerase → blocks mRNA synthesis → bactericidal against both actively dividing and semi-dormant organisms.
  • Adverse effects: hepatotoxicity (additive with isoniazid), harmless orange-red discoloration of body fluids (urine, tears, sweat), and potent, broad-spectrum hepatic CYP450 induction — accelerating metabolism of oral contraceptives (contraceptive-failure risk), warfarin, and numerous other co-administered drugs.
  • Uses: tuberculosis (both intensive and continuation phase), leprosy (combination therapy), chemoprophylaxis for close contacts of meningococcal meningitis.

Other Years Asked


Revise MBBS
Preview