Isoniazid


Description

Antibacterial agent used primarily as a tuberculostatic. It remains the treatment of choice for tuberculosis.

Read more

Pharmacology

Indication

For the treatment of all forms of tuberculosis in which organisms are susceptible.

Pharmacodynamic

Isoniazid is a bactericidal agent active against organisms of the genus Mycobacterium, specifically... Read more

Mechanism of action

Isoniazid is a prodrug and must be activated by bacterial catalase. Specficially, activation is asso... Read more

Absorption

Readily absorbed following oral administration; however, may undergo significant first pass metaboli... Read more

Protein binding

Very low (0-10%)

Volume of distribution

Information currently not available.

Clearance

Information currently not available.

Half life

Fast acetylators: 0.5 to 1.6 hours. Slow acetylators: 2 to 5 hours.

Route of elimination

From 50 to 70 percent of a dose of isoniazid is excreted in the urine within 24 hours.

Toxicity

LD50 100 mg/kg (Human, oral). Adverse reactions include rash, abnormal liver function tes... Read more


Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Mild Hepatic Dysfunction US
  • Kind: experimental
    • Percent: 10-20%
  • Progressive liver damage US
  • Kind: experimental
    • Percent: 2.3%
  • Peripheral neuropathy US
    Convulsions US
    Toxic encephalopathy US
    Optic Neuritis US
    Optic Atrophy US
    Memory Impairment US
    Nausea US
    Toxic psychosis US
    Epigastric distress US
    Vomiting US
    Hemolytic Anemia US
    Agranulocytosis US
    Aplastic Anemia US
    Sideroblastic anemia US
    Eosinophilia US
    Thrombocytopenia US
    Skin eruptions US
    Fever US
    Vasculitis US
    Lymphadenopathy US
    Pellagra US
    Pyridoxine deficieny US
    Elevated serum SGOT US
    Elevated SGPT US
    Systemic lupus erythematosus-like syndrome US
    Injection Site Irritation US
    Gynecomastia US
    Rheumatic syndrome US
    Hyperglycemia US
    Metabolic Acidosis US
    Jaundice US
    Fatal hepatitis US
    Bilirubinemia US
    Bilirubinuria US

    Contraindications

    • Regions: US
    • Patient Conditions:
        • Name: Severe adverse drug reaction
        • Drugbank Id: DBCOND0108069
        • Modification Of:
          • Base:
            • Name: Adverse Drug Reaction
            • Drugbank Id: DBCOND0055066
          • Severity:
            • Includes:
              • severe

    Food Interactions

    • Avoid aged foods (cheese, red wine), pickled foods, cured foods (bacon/ham), chocolate, fava beans, beer, unless approved by your physician.
    • Avoid alcohol.
    • Do not take calcium, aluminum, magnesium or Iron supplements within 2 hours of taking this medication.
    • Increase dietary intake of magnesium, folate, vitamin B6, B12, and/or consider taking a multivitamin.
    • Take on empty stomach: 1 hour before or 2 hours after meals.
    • Take with a full glass of water.

    Interactions

    Type in a drug name to check for interaction with Isoniazid

    The serum concentration of (R)-warfarin can be increased when it is combined with Isoniazid.
    The serum concentration of (S)-Warfarin can be increased when it is combined with Isoniazid.
    The risk or severity of serotonin syndrome can be increased when Isoniazid is combined with 2,5-Dimethoxy-4-ethylamphetamine.
    The risk or severity of serotonin syndrome can be increased when Isoniazid is combined with 2,5-Dimethoxy-4-ethylthioamphetamine.
    25-desacetylrifapentine may increase the hepatotoxic activities of Isoniazid.
    The serum concentration of 3-isobutyl-1-methyl-7H-xanthine can be increased when it is combined with Isoniazid.
    The metabolism of 3,5-diiodothyropropionic acid can be decreased when combined with Isoniazid.
    The risk or severity of serotonin syndrome can be increased when Isoniazid is combined with 4-Bromo-2,5-dimethoxyamphetamine.
    The metabolism of 4-hydroxycoumarin can be decreased when combined with Isoniazid.
    The metabolism of 5-androstenedione can be decreased when combined with Isoniazid.
    The risk or severity of serotonin syndrome can be increased when Isoniazid is combined with 5-methoxy-N,N-dimethyltryptamine.
    The serum concentration of 6-O-benzylguanine can be increased when it is combined with Isoniazid.
    The serum concentration of 7-Deazaguanine can be increased when it is combined with Isoniazid.
    The metabolism of 7-ethyl-10-hydroxycamptothecin can be decreased when combined with Isoniazid.
    The therapeutic efficacy of 7-Nitroindazole can be decreased when used in combination with Isoniazid.
    The risk or severity of serotonin syndrome can be increased when Isoniazid is combined with 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline.
    The serum concentration of 7,9-Dimethylguanine can be increased when it is combined with Isoniazid.
    The serum concentration of 8-azaguanine can be increased when it is combined with Isoniazid.
    The serum concentration of 8-chlorotheophylline can be increased when it is combined with Isoniazid.
    The metabolism of 9-aminocamptothecin can be decreased when combined with Isoniazid.

    References

      Information currently not available.

    Recent Questions