Time course of the percent functional hepatocytes after a 22 g overdose and different NAC rescue times. The black curve shows model computations of the percentage of function hepatocytes after an 22 g dose of APAP. The curve decreases well below the gray bar at the 30% level below which liver failure usually occurs. The green curve shows the time course of functional hepatocytes with rescue by 36 mM NAC given continuously for one hour starting at 2 hours after the overdose. The green curve stays well above the 30% threshold. The blue, red, cyan, and magenta curves show the time courses of functional hepatocytes if the rescue dose is given at 6, 10, 14, 18 hours respectively. The curves show clearly the importance of early rescue.