Are methotrexate-induced side effects due to differences in pharmacokinetics in children with Down syndrome and acute lymphoblastic leukemia?
We did not find evidence of differences in the pharmacokinetics of methotrexate between patients with and without Down syndrome which could explain the higher frequency of gastrointestinal toxicity and the greater need for methotrexate dose reductions in patients with Down syndrome. Hence, these problems are most likely explained by differential pharmaco-dynamic effects in the tissues between children with and without Down syndrome. Although the number of patients was limited to draw conclusions, we feel that it may be safe in children with Down syndrome to start with intermediate dosages of methotrexate (1-3 g/m(2)) and monitor the patients carefully.
The 7-day in vitro storage parameters investigated were comparable between >95% PAS 5 and 100% plasma platelets derived from both Amicus and Trima plateletpheresis devices, with the exception that lactose dehydrogenase release rate and pH were significantly higher in PAS 5 units.