Intentional overdosage with isoniazid: case report and review of literature

Singapore Med J. 1996 Apr;37(2):222-5.


Isoniazid (INH) is widely used in most prophylactic and therapeutic anti-tuberculosis regimens because of its effectiveness and low cost. Yet, INH poisoning appears to be rare. We report the first case of intentional INH overdosage in Singapore. A 26-year-old Filipino male presented with mental obtundation, recurrent seizures, metabolic acidosis and hepatic dysfunction. He was successfully treated with large doses of pyridoxine (vitamin B6). Recommendations for the management of acute INH toxicity are highlighted.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adult
  • Antitubercular Agents / poisoning*
  • Antitubercular Agents / therapeutic use
  • Drug Overdose / diagnosis
  • Drug Overdose / physiopathology
  • Humans
  • Isoniazid / poisoning*
  • Isoniazid / therapeutic use
  • Male
  • Suicide, Attempted*
  • Tuberculosis, Pulmonary / drug therapy


  • Antitubercular Agents
  • Isoniazid