Standard dosage	10 mg/kg in a single dose not to exceed 600 mg/day.
Contraindications	Hypersensitivity to the drug including history of a previous isoniazid-associated hepatic injury.
Major side effects	Transient hepatic dysfunction, gastrointestinal symptoms, hematological disturbances, particularly, thrombocytopenia, and headache.
Major drug interactions	Avoid concomitant administration of saquinavir. May accelerate the metabolism of a wide variety of drugs by inducing cytochrome P-450 enzymes.
Special points	Should be administered either 1 h before or 2 h after a meal.
Cost	Inexpensive.