2. Contents
• Introduction
• Mechanism of action
• Pharmacokinetics
• Dosage and Administration
• Contraindications
• Drug Interactions
• Adverse Reactions/Side effects
• Precautions
• Overdosage
• Patient Information
3. Synonyms and Abbreviations
• Isonicotinyl hydrazine
• Isonicotinic acid hydrazide
• INH
• H (for "hydrazide", and also
the WHO standard abbreviation)
5. • first-line medication in prevention and treatment of
Tuberculosis.
• Synthesized in the early 20th century.
• Isoniazid is available in tablet, syrup, and injectable
forms (given intramuscularly or intravenously).
• Isoniazid is manufactured from isonicotinic acid,
which is produced from 4-methylpyridine.
Isoniazid
6. CLASSIFICATION OF DRUGS USED IN ANTI-
TUBERCULOSIS TREATMENT
• ISONIAZIDE
• RIFAMPIN
• PYRAZINAMIDE
• ETHAMBUTOL
• STREPTOMYCIN
• AMIKACIN
• AMINOSALICYCLIC ACID
• CAPREOMYCIN
• CIPROFLOXACIN
• CLOFAZIMINE
• CYCLOSERINE
• ETHIONAMIDE
• LEVOFLOXACIN
• RIFABUTIN
• RIFAPENTINE
FIRST LINE DRUGS SECOND LINE DRUGS
7. MECHANISM OF ACTION
• Inhibit synthesis of Mycolic acid.
• It’s a pro drug activated by KatG.
• Resistance to INH is associated with overexpression
of inhA.
• Overproducers of inhA express low level INH
resistance & cross resistance to ethionamide.
• KatG mutants express high level of INH resistance &
usually no cross resistance to ethionamide.
8. Pharmacokinetics
• Absorption: T max is 1 to 2 h.
• Distribution: Diffuses readily into cerebrospinal, pleural,
and ascitic fluids, tissues, organs, saliva, sputum, feces,
placental barrier, and in breast milk.
• Metabolism: Primarily by acetylation and
dehydrazination.
• Elimination: 50% to 70% excreted in the urine in 24 h.
9. Dosage and Administration
• Tuberculosis:
Adults
• PO / IM 5 mg/kg/day as single daily dose (max,
300 mg/day) or 15 mg/kg 2 to 3 times/wk (max, 900 mg).
• Infants and Children
• PO / IM 10 to 20 mg/kg/day in single daily dose (max,
300 mg/day) or 20 to 40 mg/kg 2 or 3 times/week (max,
400 mg).
15. Patient Information
• Advise patient to minimize daily alcohol consumption while
taking isoniazid because of the increased risk of hepatitis.
• Instruct patient to report the following symptoms to health
care provider: weakness; fatigue; loss of appetite; nausea and
vomiting; yellowing of skin or eyes; darkening of urine;
numbness or tingling in hands or feet.
• Emphasize to patient that treatment will be lengthy and that
patient must complete entire course of therapy. Relapse of
tuberculosis is higher if chemotherapy is discontinued
prematurely.
• Advise patient to return for laboratory follow-up.
• Caution patient not to perform activities that require mental
alertness if adverse CNS symptoms occur.