INH drug 'Isoniazid'

Isoniazid drug of choice fort treatment of Tuberculosis

1. Isoniazid
Prepared by:
Nahry Omer Muhammad

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)

4. Trade Name
•Nydrazid:
-Injection: 100mg/ml
•Isoniazid
- Tablets 100 mg
- Tablets 300 mg
- Tablets 500 mg
- Syrup 50 mg/5 mL
•Isotamine
•Laniazid

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).

10. Contraindications
•Previous isoniazid-associated hepatic injury
•Drug fever
•Chills
•Arthritis
•Acute liver disease.
•Pregnant women.
•Breast feeding women

11. Drug Interactions
•Aluminum salts
•Carbamazepine
•Disulfiram
•Enflurane
•Hydantoins
•Rifampin

12. Adverse Reactions
•CNS: Peripheral neuropathy; convulsions; toxic encephalopathy; optic
neuritis and atrophy; memory impairment; toxic psychosis.
•Dermatologic: Morbilliform, maculopapular, purpuric, or exfoliative skin
eruptions.
•GIT: Nausea; vomiting; epigastric distress.
•Hematologic: Agranulocytosis; hemolytic, sideroblastic, or aplastic
anemia; thrombocytopenia; eosinophilia.
•Hepatic: Hepatotoxicity, including elevated serum transaminase levels,
bilirubinemia, bilirubinuria, jaundice, severe and sometimes fatal hepatitis.
•Metabolic: Pyridoxine deficiency; pellagra; hyperglycemia; metabolic
acidosis; hypocalcemia; hypophosphatemia.
•Miscellaneous: Gynecomastia; rheumatic syndrome; systemic lupus
erythematosus-like syndrome; local irritation at IM injection site.

13. Precautions
•Pregnancy
•Lactation
•Hypersensitivity
•Renal Function
•Hepatic Function
•Pyridoxine administration

14. Overdosage
Symptoms:
Nausea, vomiting.
dizziness, slurring of speech.
blurring of vision, visual hallucinations.
respiratory distress, CNS depression.
stupor, coma.
severe seizures (Diazepam (Valium), 5 to 10 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.

16. Referneces:
•Katzung & Trevor’s Pharmacology/Examination &
Board Review/Sixth edition 2002
•www.drugs.com
•www.wikipedia.org
•www.dictionary.reference.com
•www.webmd.com
•www.fda.gov
•www.floridarehab.com

17. Thank You