This study was performed to evaluate the aggregation changes in the wh
ole blood samples of children with epilepsy receiving valproic acid. A
total of 25 patients and 15 healthy volunteer adults were included in
the study. Platelet aggregation study was performed in whole blood by
impedance aggregometry. Platelet counts, the bleeding times, and clot
ting times of the patients were within normal limits. The aggregation
time and maximum aggregation values revealed no significant difference
except for those with 3 mu g/ml collagen (p<0.01) between the two gro
ups. Serum valproic acid levels of the children did not correlate with
the maximum aggregation values induced by different concentrations of
aggregating agents except for 20 mu M ADP (r=-0.430, p<0.05). We conc
luded that the use of valproic acid does not result in thrombocytopeni
a and platelet dysfunction within therapeutic limits and the drug is r
eliable in the management of epilepsy.