Emergency department management of children with acute isoniazid poisoning

We suggest that the following therapeutic regimen be followed in cases of isoniazid poisoning in children. In cases of intractable seizure activity in a child which remains unexplained, consider isoniazid poisoning. Give pyridoxine as an intravenous bolus to all children in whom isoniazid toxicity is suspected, who exhibit seizure activity and are known to have been exposed to isoniazid, or who have a history of ingesting one gram or more of isoniazid. It should be given on a gram-for-gram basis, and the clinician need not await serum isoniazid levels before administering pyridoxine. It can be safely given at a rate of five grams per three minutes in a 50 ml volume. In fact, serum isoniazid determinations are not available in many emergency departments and have not been shown to correlate closely with symptomatology. When available, serum isoniazid levels at best are subject to variability owing to sampling procedures (serum protein must be removed within two hours of sampling). The result is that serum isoniazid levels play only a minor role in the emergency department management of isoniazid poisoning. To potentiate the antidotal effects of pyridoxine, diazepam (0.1 mg/kg) may be given intravenously, preferably at a second intravenous site. Because the lactic acidosis seen after seizures resolves spontaneously, and because metabolic alkalosis may result following excess lactate loading, administration of bicarbonate is usually not necessary, and may be harmful in some cases. After pyridoxine treatment, syrup of ipecac may be given to empty the stomach.(ABSTRACT TRUNCATED AT 250 WORDS)