Observation and patient disposition after isoniazid poisoning

Admit patients with suspected isoniazid ingestions for observation. Discharge them if they remain asymptomatic for at least 12 hours after isoniazid ingestion.

Patients with severe isoniazid poisoning (coma, seizures, metabolic acidosis or evidence of serotonergic toxidrome) should be admitted to an intensive care unit.

Due to isoniazid’s monoamine oxidase inhibitor (MAOI) effects, advise patients to follow a tyramine-free diet for 3 days after symptoms resolve.

Sedative drugs can continue to cause significant cognitive impairment for several days following exposure. Advise patients not to drive or operate machinery for at least 3 days after discharge.