Spurious hyperbilirubinemia caused by naproxen.

Objective: To confirm that the naproxen metabolite O-desmethylnaproxen interferes with the Jendrassik and Grof method for total bilirubin and was a possible cause of spurious hyperbilirubinemia in a case of naproxen overdose.

Design And Methods: Plasma was spiked with naproxen or O-desmethylnaproxen before total and direct bilirubin analysis.

Results: O-desmethylnaproxen concentration showed a linear relationship with measured total bilirubin.

Evaluation of glucose tolerance in cystic fibrosis: comparison of 50-g and 75-g tests.

Background: The recommended tests for evaluation of glucose tolerance in cystic fibrosis are the fasting blood glucose (FBG) and the 75-g, fasting, 2-h oral glucose tolerance test (OGTT). We compared a 50 g, non-fasting, 1-h glucose challenge test (GCT) to the standard OGTT.

Methods: During their regularly scheduled visit to the cystic fibrosis clinic, patients underwent a 50-g, non-fasting 1-h GCT and were asked to complete a standard 75-g, fasting, 2-h OGTT within one week of their clinic visit.