Clinical Pharmacokinetics

, Volume 19, Issue 2, pp 167–169 | Cite as

Allopurinol Influences Aminophenazone Elimination

  • Michael Barry
  • John Feely
Pharmacokinetic Case Report

Summary

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 < 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.

Keywords

Warfarin Theophylline Xanthine Oxidase Allopurinol Mercaptopurine 

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Copyright information

© Adis International Limited 1990

Authors and Affiliations

  • Michael Barry
    • 1
    • 2
  • John Feely
    • 1
  1. 1.Department of Pharmacology and Therapeutics, Trinity College Medical SchoolSt Jame’s HospitalDublinIreland
  2. 2.Department of Pharmacology and TherapeuticsUniversity of LiverpoolLiverpoolEngland

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