This study was approved by the ethics committee of South Egypt Cancer Institute, Assiut University, Assiut, Egypt. After obtaining a written informed consent, 90 American Society of Anesthesia (ASA) I-II patients aged 30-50 years and scheduled for major abdominal cancer surgery were included in the study. Patients with a known allergy to the study drugs, significant cardiac, respiratory, renal or hepatic disease, coagulation disorder, infection at the site of intrathecal injection, drug or alcohol abuse, BMI > 30 kg/m2 , and psychiatric illnesses that would interfere with perception and assessment of pain were excluded from the study.