The mechanisms of the variability in the intestinal absorption of nucleoside drugs

The findings in the present study indicate that the variable bioavailability (F) of mizoribine is one of the factors for the interindividual pharmacokinetic variability of the drug in healthy volunteers and adult and pediatric recipients of renal transplantation, and that the genetic polymorphism of concentrative nucleoside transporter (CNT) 1 is partly involved in the variable F of mizoribine. In addition, the membrane transport of mizoribine in intestinal epithelial cells is mediated by CNT1, CNT2, equilibrative nucleoside transporters (ENTs), and unidentified efflux transporter(s).