Marco is the hospital's pharmacist. He is played by actor Marco Pelaez. He has appeared in five episodes, always in the hospital's pharmacy next to the clinic. In Occam's Razor, he shows great annoyance while House searches his stock of Colchicine. In Detox, House gets mad at him when the hospital's supply of Vicodin has been mis-shipped. In Love Hurts, he has to inform House that the pharmacy supplier has mis-shipped the hospital's supply of Vicodin. In Merry Little Christmas, he has to suffer House's wrath of being cut off a floating prescription.