Acute isoniazid exposures and antidote availability

Pediatr Emerg Care. 1999 Apr;15(2):99-101. doi: 10.1097/00006565-199904000-00005.


Background: Over the past 10 years the reported incidence of acute isoniazid (INH)-related poisonings has increased, with 507 cases reported in 1996. Parenteral pyridoxine is the antidote for INH-induced seizures, but 5-g aliquot recommended to treat an ingestion of unknown quantity of INH is not always readily available to emergency physicians.

Objective: To determine the hospital availability of pyridoxine.

Methods: One hundred thirty questionnaires were distributed nationwide to the pharmacies and emergency departments (ED) of hospitals containing pediatric emergency medicine (PEM) fellowships and/or emergency medicine (EM) residencies. Questions were posed regarding the availability, quantity, location, and deemed importance of pyridoxine at each institution.

Results: Responses were received from 81% of the hospitals with fellowships and 80% of the hospitals with residencies. Half of the former and one third of the latter reported not having the recommended 5-g aliquot available. Eighty percent of the hospitals with PEM programs and 71% with EM residencies with an adequate stock store it in the hospital's pharmacy, as opposed to in the ED. Thirty-four states were represented, 18 of which have experienced an increase in tuberculosis (TB) from 1993 to 1994; 6/18 (33%) of those did not have the pyridoxine available, and 7/18 (39%) did not deem it necessary.

Conclusions: Our results imply that between one third and one half of the respondents would be ill-equipped to treat acute INH neurotoxicity. Establishing regional distribution centers may alleviate this deficiency, specifically in urban areas with a high incidence or a positive percent increase in TB.

MeSH terms

  • Acute Disease
  • Antidotes / supply & distribution*
  • Antitubercular Agents / poisoning*
  • Child
  • Drug Storage
  • Emergency Medicine / education
  • Emergency Service, Hospital / standards*
  • Fellowships and Scholarships
  • Humans
  • Internship and Residency
  • Inventories, Hospital / statistics & numerical data*
  • Isoniazid / poisoning*
  • Nervous System Diseases / chemically induced
  • Nervous System Diseases / drug therapy
  • Pediatrics / education
  • Poisoning / drug therapy
  • Pyridoxine / supply & distribution*
  • Surveys and Questionnaires
  • United States


  • Antidotes
  • Antitubercular Agents
  • Pyridoxine
  • Isoniazid