[Changes in platelet count and mean volume of platelet after administration of icosapentaenoic acid ethyl-ester, and factors that may affect those changes].

A total of 34 patients, aged 43 to 86 years old (mean 65), consisting of 26 males and 8 females, with thrombotic or arteriosclerotic diseases were orally given highly purified eicosapentaenoic acid ethyl-ester formulation (IPA-E) for 12 weeks without changing regular food intake. Changes in platelet count (PLT), mean platelet volume (MPV), platelet-crit (Pct) and change of distribution width of platelet size (PDW), and factors affecting the changes were studied administration, dose of IPA-E, age, sex, smoking habits, complications of diabetes mellitus and hyperlipidemia, and concomitant drugs such as calcium antagonists or diuretics. With daily administration of 1800 or 900 mg of IPA-E, PLT and Pct began to decrease after four weeks and decreased significantly after eight weeks until the completion of administration. After the 12th week, the MVP became smaller than the preadministration level, while PDW did not change significantly during the entire period of administration. The volume and rates of changes in PLT, MPV and Pct during administration for 12 weeks correlated negatively with those preadministration values. The PLT, MPV and Pct decreased significantly in both the 1800 and 900 mg groups compared to values before administration. There were no significant differences in changes between the two groups. The plasma IPA concentration in the 12th week of the 1800 mg group was significantly higher than that of the 900 mg group. The rate of changes in Pct had a significantly negative correlation with the achieved IPA concentration. The age, smoking habits, complications of diabetes mellitus, or concomitant drugs of calcium antagonists or diuretics did not affect the changes of platelet parameters significantly. The PLT and Pct in male patients decreased significantly, but no significant changes were observed in female patients. The PLT and Pct in patients with IIb and IV hyperlipidemia decreased significantly compared to those in normolipidemic or IIa hyperlipidemic subjects. The study demonstrated that IPA-E improved platelet parameters, suggesting IPA-E could prevent progression of thrombotic and arteriosclerotic diseases, IPA-E was particularly effective in male patients or patients with Type IIb or IV hyperlipidemia. Although a daily dose of 900 mg was effective, 1800 mg was even more effective.