* Part A will compare the PK of oral digoxin alone and in combination with an IV infusion of rolapitant.
* Part B will compare the PK of an oral dose of sulfasalazine alone to the PK of an oral dose of sulfasalazine in combination with an IV infusion of rolapitant
* Part C will compare the PK of an oral dose of the Cooperstown Cocktail (midazolam, omeprazole, warfarin, caffeine, and dextromethorphan) alone and when given in combination with an IV infusion of rolapitant.