Flavoxate has not previously been reported as a cause of hepatotoxicity. The case patient, who had Gilbert's syndrome, received flavoxate that, in association with tibolone, might have produced a toxic effect. Several UDP-glucuronosyltransferase enzymes exist but, according to Guay et al., there is no clear indication of which is involved in flavoxate metabolism.
Patients with Gilbert's syndrome mutations are relatively common (10-13% of the population). Even if these patients are considered healthy, great care should be taken when a polytherapy is administered, because different drugs can be metabolized by the same glucuronosyltransferase enzyme of which the activity is reduced (as it was in this case). Further studies are needed to determine whether genetic analysis of the TATA box of the UGT1A1 gene should be considered as a routine test before starting a combination therapy with a drug that is glucurono-conjugated
Correspondence: *Centro Studi Fegato, AREA Science Park, Basovizza, Building Q, SS 14, km 163.5, 34012 Trieste, Italy. Email email@example.com
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Nat Clin Pract Gastroenterol Hepatol. 2007;4(7):403-408. © 2007
Nature Publishing Group
The authors declared no competing interests.
Cite this: Drug-Induced Acute Cholestatic Liver Damage in a Patient with Mutation of UGT1A1 - Medscape - Jul 01, 2007.