PROBLEM TO BE SOLVED: To provide a pharmaceutical composition and such composition for increasing the level of eicosapentaenoic acid in plasma, serum and / or red blood cells (RBC), and / or for treating or preventing a cardiovascular-related disease. It contains at least 96% by weight of eicosapentaenoic acid ethyl ester (E-EPA) and 0.5% by weight or less of docosahexaenoic acid (DHA) derivative, and is intended to be administered in an amount of about 4 g per day. Composition. [Selection diagram] Fig. 1【課題】血漿、血清及び／又は赤血球（ＲＢＣ）のエイコサペンタエン酸レベルを増加させるための、並びに／或いは心血管関連疾患を処置又は予防するための、医薬組成物及びかかる組成物の提供。【解決手段】少なくとも９６重量％のエイコサペンタエン酸エチルエステル（Ｅ－ＥＰＡ）、及び０．５重量％以下のドコサヘキサエン酸（ＤＨＡ）誘導体を含み、１日当たり約４ｇ投与されるためのものである、組成物。【選択図】図１
