Abstract
The effects of allopurinol on the plasma clearance and metabolism of'theophylline in man were investigated under single-dose and multiple-dosing conditions. No change in theophylline clearance was found with the concomitant use of allopurinol but 1-methylxanthine (IMX), a theophylline metabolite not previously described in man, was detected in urine during control and allopurinol treatment phases under both single- and multiple-dosing conditions. IMX excretion increased at the expense of 1-methyluric acid (IMU) during the allopurinol treatment phase. It is proposed that the secondary biotransformation of IMX to IMU is mediated by xanthine oxidase.
Original language | English |
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Pages (from-to) | 660-667 |
Number of pages | 8 |
Journal | Clinical Pharmacology and Therapeutics |
Volume | 26 |
Issue number | 5 |
DOIs | |
Publication status | Published - Nov 1979 |