Inclusion Criteria:  age >18, <40 years; American Society of Anesthesiologists physical status I or II; term pregnancy singleton pregnancy; elective cesarean delivery under spinal anesthesia  Exclusion Criteria:  Patients with a history of diabetes mellitus other than gestational diabetes, hypertension, body mass index >40 kg/m2, complicated pregnancy, allergy to study drugs, long QT syndrome, Contraindication to spinal anesthesia Patients who required general anesthesia were withdrawn from the study.