Hepatitis A impairs the function of human hepatic CYP2A6 in vivo

Hepatitis virus A (HVA) is a worldwide sporadic disease but its effects on pharmacokinetics and individual drug responses have not been studied. In this study, the 7-hydroxycoumarin (7OHC) excretion test used in vivo as a bioindex of hepatic CYP2A6 activity was performed in 20, previously healthy, acute jaundice HVA patients. Volunteers with an acute HVA were treated with one p.o. administration of 5 mg coumarin (Venalot®). Among the patients, 11 were children (6–10 years; two girls and nine boys), the rest (15–40 years old) consisted of two men and seven women. Urinary excretion of 7OHC was measured after overnight fasting in four fractions: 0 h before any medication (to detect if any basal 7OHC excretion exits), and after a 5-mg coumarin capsule p.o., 0–2, 2–4 and 4–8 h fractions were collected and urine volumes were recorded. Urinary excretion of 7-hydroxycoumarin occurred to a similar extent in healthy adults and children. The first 2-h 7OHC excretion was decreased by 26% ( P