• Tuberculosis

Isoniazid Generic Name & Formulations

General Description

Isoniazid 300mg; scored tabs.

Pharmacological Class

Isonicotinic acid.

How Supplied

Contact supplier.

Isoniazid Indications


Prophylaxis and treatment of susceptible tuberculosis.

Isoniazid Dosage and Administration


Prophylaxis: 300mg once daily. Active infection: 5mg/kg daily; max 300mg once daily. Do not interrupt therapy.


Prophylaxis: 10mg/kg once daily; max 300mg daily. Active infection: 10–20mg/kg once daily; max 500mg daily. Do not interrupt therapy.

Isoniazid Contraindications


Drug-induced hepatitis. Previous isoniazid-associated hepatic injury. Severe adverse reactions to isoniazid (eg, drug fever, chills, arthritis). Acute liver disease of any etiology.

Isoniazid Boxed Warnings

Not Applicable

Isoniazid Warnings/Precautions


Impaired renal or hepatic function. Monitor hepatic and ocular function. Alcoholism. Diabetes. Increased risk of liver damage with increasing age. Multiple drug therapy and concomitant pyridoxine may be necessary. Pregnancy. Nursing mothers.

Isoniazid Pharmacokinetics

See Literature

Isoniazid Interactions


Potentiates phenytoin. Alcohol increases risk of hepatitis. Pyridoxine deficiency increases risk of neuropathy.

Isoniazid Adverse Reactions

Adverse Reactions

Peripheral neuropathy (esp. in slow acetylators), elevated serum transaminases (SGOT; SGPT), bilirubinemia, bilirubinuria, jaundice, hepatitis (may be fatal), nausea, vomiting, epigastric distress, pancreatitis, blood dyscrasias, hypersensitivity reactions (eg, skin eruptions, TEN, DRESS), pyridoxine deficiency, hyperglycemia, pellagra, metabolic acidosis, gynecomastia, rheumatic syndrome, SLE-like syndrome.

Isoniazid Clinical Trials

See Literature

Isoniazid Note


Formerly known under the brand names INH, Laniazid.

Isoniazid Patient Counseling

See Literature