Interindividual variability of coumarin 7-hydroxylation in a Turkish population.
One hundred healthy Turkish volunteers (70 male, 30 female) aged from 19 to 56 years were given 5 mg coumarin p.o. after an overnight fast. Urine samples were collected before and 2, 4 and 8 h after drug administration. The extent and rate of formation of 7-OH-coumarin (7OHC) was determined by the urinary excretion of the metabolite as measured with the fluorometric method. On average, 80% of 7OHC formed was excreted in 2 h. The total amount of 7OHC formed was 59.8% (21.5%) (mean and SD, n = 100, range 17-100%) of the given dose. The percentage of 7OHC excreted during the first 2 h compared with the 7OHC excretion at 8 h was a constant and stable individual characteristic for the rate of the formation of 7OHC ('2 h coumarin test'). Although four individuals had relatively slow coumarin test values (34-40%), no clear-cut polymorphism in the rate of 7OHC formation was found. However, 7OHC formation was lower in males and in cigarette smokers.
Iscan
M
M
Department of Toxicology, Faculty of Pharmacy, Ankara University, Turkey.
Rostami
H
H
Iscan
M
M
Güray
T
T
Pelkonen
O
O
Rautio
A
A
D000328:Adult; D000367:Age Factors; D003374:Coumarins / Q000378:metabolism*; D005260:Female; D006801:Humans; D006900:Hydroxylation; D007206:Individuality; D008297:Male; D008875:Middle Aged; D010946:Plants, Medicinal; D011110:Polymorphism, Genetic / Q000235:genetics*; D012737:Sex Factors; D012907:Smoking; D014421:Turkey
D003374:Coumarins; C030123:coumarin