title: Allopurinol influences aminophenazone elimination.
abstract: The authors observed an interaction between allopurinol and both theophylline and warfarin in 2 patients. To determine the possible effect of allopurinol on hepatic oxidative metabolism a [14C]-aminophenazone (aminopyrine) breath test was performed before and during treatment with allopurinol 100mg daily in 5 patients with hyperuricaemia. Allopurinol prolonged the [14CO2]-aminophenazone half-life from 72 +/- 13 to 104 +/- 16 minutes (mean +/- SEM, p less than 0.05). It is possible that allopurinol may produce clinically significant drug interactions through an inhibitory effect not only on xanthine oxidase metabolism but also on oxidative metabolism.
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity College Medical School, St James's Hospital, Dublin, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Barry
authors.forename: J
authors.initials: J
authors.lastname: Feely
mesh_terms: D000493:Allopurinol / Q000494:pharmacology*; D000632:Aminopyrine / Q000493:pharmacokinetics*; D001944:Breath Tests; D004347:Drug Interactions; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D014527:Uric Acid / Q000652:urine
chemical_list: D000632:Aminopyrine; D014527:Uric Acid; D000493:Allopurinol