Glatstein M, et al. - Given the use of pyridoxine (vitamin B6) as an antidote for isoniazid (INH) overdose, especially in intentional ingestions, the researcher sought to determine and document the role of pyridoxine in the treatment of patients with intentional ingestion of INH and to report their experience. They recognized intentional ingestion of INH as one of the causes of drug-induced seizures. Mortality could be prevented with early recognition and specific treatment with pyridoxine. Observations revealed a substantial risk of multiple seizures among patients with large-dose intentional ingestions that can be treated successfully with 1 g of pyridoxine intravenously or 1 g of pyridoxine per gram of isoniazid ingestion. This antidote was observed to be safe and efficacious. In some circumstances, consideration can be given to administering pyridoxine prophylactically.