Prolonged toxicity following massive ingestion of sustained-release theophylline preparation

Massive ingestion of sustained-release theophylline preparations in three patients was treated with gastric lavage and repeated dosages of orally-administered activated charcoal. Therapy was initiated promptly; however, two patients had their highest theophylline levels documented six to 12 hours after ingestion, and theophylline levels on arrival at the hospital were significantly lower than the maximal level documented. All three patients had prolonged elevations of the level, with markedly delayed half-lives of the drug. Overdosages due to sustained release preparations may lead to prolonged toxicity and require aggressive and continuous therapy.