Figure 10-3 The context-sensitive half-times for commonly used intravenous anesthetic drugs are displayed. The context-sensitive half-time is the time for the plasma level of the drug to drop 50% after cessation of infusion. The duration of infusion is plotted on the horizontal axis. Note that the rapidity with which the drug level drops is directly related to the time of infusion (i.e., the longer the drug is infused, the longer the half-time). Also note that etomidate, propofol, and ketamine have significantly shorter half-times than thiopental and diazepam do, which makes them more suitable for prolonged infusion.