Purpose: Rosuvastatin has been widely used in combination with olmesartan for the treatment of dyslipidemia accompanied by hypertension. With no information currently available on the interaction between the 2 drugs, a pharmacokinetic study was conducted to investigate the influence of rosuvastatin on olmesartan and vice versa when the 2 drugs were coadministered. The purpose of this study was to investigate the pharmacokinetic profile of coadministration of the rosuvastatin 20-mg tablet and the olmesartan 40-mg tablet and the associated drug drug interaction in healthy Korean male volunteers. Methods: This was a randomized, open-label, 3-period, multiple-dose crossover study. Eligible subjects were aged 20 to 50 years and within 20% of their ideal body weight. After being randomly assigned to 6 groups of equal number, subjects received each of the following 3 formulations once a day for 7 consecutive days with an 8-day washout period between the formulations: rosuvastatin 20-mg tablet, olmesartan 40-mg tablet, and coadministration of the rosuvastatin 20-mg tablet and the olmesartan 40-mg tablet. Blood samples were collected up to 72 hours after dosing, and pharmacokinetic parameters were determined for rosuvastatin, its active metabolite (N-desmethyl rosuvastatin), and olmesartan. Adverse events were evaluated based on subject interviews and physical examinations. Findings: Among the 36 enrolled subjects, 34 completed the study (mean [range] age, 28.6 [23-49] y; mean [range] weight, 66.4 [52.2-78.7] kg). The 90% CIs of the geometric mean ratios for the primary pharmacokinetic parameters for the coadministration of the 2 drugs to the mono-administration of each drug were 85.14% to 96.08% for AUC(tau) and 81.41% to 97.48% for C-ss,C-max for rosuvastatin, and 77.55% to 89.48% for AUC(tau) and 75.62% to 90.12% for C-ss,C-max for N-desmethyl rosuvastatin; those values were 95.61% to 102.57% for AUC(tau) and 91.73% to 102.98% for C-ss,C-max for olmesartan. Dizziness was the most frequently noted adverse drug reaction, occurring in 1 subject receiving mono-administration of rosuvastatin, 1 subject receiving mono-administration of olmesartan, and 4 subjects receiving coadministration of rosuvastatin and olmesartan. All the adverse events were expected, and there was no significant difference in the incidence between the 2 formulations. Implications: This study suggests that rosuvastatin and olmesartan did not significantly influence each other's pharmacokinetics when coadministered. Although the pharmacokinetics of N-desmethyl rosuvastatin were influenced by olmesartan, such interactions were considered clinically insignificant. All 3 formulations were well tolerated, and no serious adverse events or drug reactions were noted. (C) 2014 Elsevier HS Journals, Inc. All rights reserved.