N-acetylcysteine (NAC) Administration (Night before and t = 0, t = 5) NAC is a cysteine donor and antioxidant approved for use in humans, orally or intravenously. When given to treat acetaminophen overdose, NAC is typically given as a large bolus (~120-150 mg/kg over 15-60 minutes), followed by continued administration over the next 20-36 hours. NAC has also been used as a cysteine donor for malnourished children, HIV infected individuals, and patients with pulmonary disease. When administered orally, the sulfur content of NAC reduces palatability. As a result, it is typically mixed with soda, juice, or a flavored drink mix. A recent study found that NAC, administered as a 75mg/kg oral bolus mixed with flavored drink mix, was well tolerated and markedly influenced 3-methylhistidine levels. The investigators will follow this strategy, administering 50 mg/kg doses mixed with flavored drink.