Dosing for this study will begin at 2 grams/m2/day, which is about one-fifth (1/5) the dose used for other disorders. The reason for starting the dose lower in MCAD patients is that Ravicti is metabolized by the MCAD enzyme. Following the initial dose, blood will be drawn from the IV every two hours for 8 hours. These blood studies will check the levels of Ravicti in the subject's blood and monitor how the subject's body metabolizes them. The subject will be discharged 8 hours after drug administration. Following discharge, the subject will take Ravicti every day for two weeks.