Of these, 60 patients were excluded for the following reasons: patients with QTc interval ≥ 450 ms (n = 2), received drugs affected the P450 or CYP2B6 within thelast 2 weeks (n = 4), history of alcohol/drug abuse and nasopharyngeal surgery (n = 9), allergies to eggs or soy products (n = 12), BMI > 30kg/m2 (n = 2), difficult airway (n = 2), severe hypertension,diabetes,liver and kidneydysfunction (n = 17), patients refusal to sign the consent forms (n = 8), patients unable to communicate or cooperate (n = 4). Here, CYP2B6 is linked to Allergy.