Participants were randomized equally into eight regimen sequence groups, 20 participants each. Participants randomized to Sequence Groups 1 and 2, 3 and 4, 5 and 6 and 7 and 8 were called proton pump inhibitor (PPI) Groups 1, 2, 3, and 4, respectively. Each sequence group consists of 2 regimens. Sequence Groups 1, 3, 5 and 7 dosed Regimen A (75 mg clopidogrel) for Days 1-9 of Period 1 and then crossed over to one of the following 4 regimens for Days 1-9 of Period 2: Regimen B (75 mg clopidogrel + 30 mg lansoprazole), Regimen C (75 mg clopidogrel + 60 mg dexlansoprazole), Regimen D (75 mg clopidogrel + 80 mg [2x40 mg] omeprazole), or Regimen E (75 mg clopidogrel + 40 mg esomeprazole). Sequence Groups 2, 4, 6 and 8 began with either Regimen B, C, D or E for Period 1 and then crossed over to Regimen A for Period 2.