Indications for Isoniazid:

Prophylaxis and treatment of susceptible tuberculosis.


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.


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


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.

Pharmacologic Class:

Isonicotinic acid.


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

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.


Formerly known under the brand names INH, Laniazid.

How Supplied:

Contact supplier.

Pricing for Isoniazid

300mg tablet (Qty: 30)
Appx. price $8