Fig. 9. The time course for the probability of no response to voice after each of the dosing schemes in table 5. Simulations are based on pharmacokinetic and pharmacodynamic parameters in table 7 using the three-drug interaction model (equation 13). Midazolam (M) is administered at time = 0 min; propofol (P) and alfentanil (A) are administered at time = 2 min. Doses are selected to cause loss of response to voice in 95% of individuals at time = 4 min. The time course for each combination is labeled as they cross the horizontal line at P = 0.05.