Antimicrobial
Isoniazid
KatG-activated mycolic acid synthesis blocker
eye-soh-NY-uh-zid
High-yield clue
Isoniazid is a prodrug activated by KatG that then inhibits InhA to block mycolic acid synthesis; katG loss is a classic resistance route.
Overview
A key antimycobacterial prodrug studied for blocking mycolic acid synthesis after activation by the mycobacterial catalase-peroxidase KatG.
Classification
- Antimycobacterial prodrug
- Activated by KatG catalase-peroxidase
- Inhibits InhA (enoyl-ACP reductase)
- Blocks mycolic acid synthesis
Lab & identification clues
- Forms INH-NAD adduct inhibiting InhA concept
- katG mutation resistance vocabulary
- inhA promoter mutation cross-resistance concept
Associations
- Latent and active tuberculosis study vocabulary
- Pyridoxine (B6) depletion / neuropathy concept
- Hepatotoxicity monitoring study framing
Commonly confused with
- Rifamycins
- Ethambutol
Frequently asked questions
What is Isoniazid?
A key antimycobacterial prodrug studied for blocking mycolic acid synthesis after activation by the mycobacterial catalase-peroxidase KatG.
What is the high-yield clue for Isoniazid?
Isoniazid is a prodrug activated by KatG that then inhibits InhA to block mycolic acid synthesis; katG loss is a classic resistance route.
What is Isoniazid associated with?
Isoniazid is associated with Latent and active tuberculosis study vocabulary, Pyridoxine (B6) depletion / neuropathy concept, and Hepatotoxicity monitoring study framing.
What is Isoniazid commonly confused with?
Isoniazid is commonly confused with Rifamycins and Ethambutol.
Original mechanism summary for microbiology study. Sources checked: CDC antimicrobial-resistance guidance, NCBI Bookshelf Medical Microbiology, and standard coursework frameworks; reviewed 2026-06. Covers class, mechanism, and resistance vocabulary only; no prescribing, dosing, or patient-specific treatment guidance.