CYP2B6 and Allergy: Thirty-five patients were excluded from this study for the following reasons: QTc interval ≥450 ms (n = 1); receipt of drugs that may have affected the CYP450 enzymes, especially CYP2B6, within the last 2 weeks (n = 4); history of alcohol/drug abuse and nasopharyngeal surgery (n = 9); known allergies to eggs or soy products (n = 5); body mass index >30 kg/m2 (n = 2); difficult airway (n = 1); severe hypertension, diabetes, or liver and kidney dysfunction (n = 8); refusal to sign the consent forms (n = 3); and inability to communicate or cooperate (n = 2).