Pyrazinamide
PYRAZINAMIDE (Z)
INTRODUCTION:
- Weakly bactericidal drug.
- Most effective against slowly replicating bacteria in acidic media.
- Acidic medium – Sites of inflammation & intracellular sites.
- Hence, potent sterilizing effect.
- Risk of relapse is reduced.
- Good CSF penetration.
- Half-life of prolonged during renal & hepatic impairment.
MECHANISM OF ACTION:
- Pyrazinamide mycobacterial complex→Pyrazinamidase pncA→ Pyrazinoic acid→ Inhibits plasma membrane synthesis.
USES:
- Effective only against intracelluar mycobacterium.
- Drug usually highly effective during 1st 2months (within inflammatory period).
- First line ATT in children Streptomycin & Pyrazinamide.
- Including Z in combination therapy – duration of treatment is reduced.
ADVERSE EFFECTS:
- Non-gouty arthralgia (40% patients).
- Due to hyperuricemia.
- Precipitates gout & usually asymptomatic.
- Hepatitis (Dose-dependent effect).
- Phtotosensitivity.
- Porphyria.
- Fever, flushing, rashes, loss of diabetes control.
- Rare adverse effects
- Gastrointestinal & cutaneous reactions.
- Sideroblastic anaemia.
Exam Question
- Pyrazinamide is a bactericidal drug.
- Hyperuricemia is a recognized side effect of pyrazinamide.
- Pyrazinamide precipitates gout.
- Pyrazinamide is anti-tubercular drug not given in liver disease.
- First line ATT in children – Streptomycin & Pyrazinamide.
- Maximum liver toxicity is seen with Pyrazinamide anti -TB drug.
Don’t Forget to Solve all the previous Year Question asked on Pyrazinamide
