The relationship between plasma ibuprofen concentrations and toxicity in acute ibuprofen overdose.

1. The information available from the literature and from a prospective survey of ibuprofen overdose being undertaken by the London centre of the National Poisons Information Service (NPIS) was examined utilizing the Generalized Linear Interactive Modelling (GLIM) statistical computing package. 2. This confirmed that timed ibuprofen plasma concentrations were related to the symptoms of tachycardia, dizziness, tinnitus, ocular symptoms and coma/stupor as well as to reversible renal impairment and plasma hepatic enzyme elevation. 3. The best model of the relationship between symptomatic toxicity and timed ibuprofen plasma concentrations, was an exponential equation in time. Because of the lack of specificity or sensitivity in this model, and absence of demonstrable clinical advantages from its application, we do not recommend its use as a guide to predict toxicity. 4. However analysis of a larger information base utilizing similar methodology could, by increasing the statistical power of the resultant model, provide a useful means of predicting ibuprofen toxicity. 5. A previously postulated relationship between post-ingestion ibuprofen plasma concentrations and toxicity was not confirmed.