Duloxetine Potentiates the Analgesic Efficacy of Intrathecal Morphine

Duloxetine Potentiates the Analgesic Efficacy of Intrathecal Morphine in Major Abdominal Cancer Surgery

Duloxetine is a serotonin-norepinephrine reuptake inhibitor primarily used for treatment of major depression and anxiety. Duloxetine also has been used in the treatment of chronic pain conditions, such as osteoarthritis and musculoskeletal pain. There are few studies examining its effect for acute pain. The objective of this study is to evaluate the analgesic effect of duloxetine combined with intrathecal morphine for patients subjected to major abdominal cancer surgery

Patients will receive duloxetine, 60 mg tablet 2 hour before operation and will be anesthetized by combined spinal-general anesthesia that includes: spinal anesthesia with morphine 0.3 mg delivered in L4-5 inter spinous space. General anethseia: Induction of anesthesia was done by intravenous fentanyl, 2 µg / kg and propofol 1 - 2 mg / kg. Endotracheal intubation was achieved by cis-atracurium, 0.15 mg / kg. Maintenance of anesthesia was done by isoflurane and cis-atracurium, 0.03 mg / kg on demand. Additional intraoperative analgesia was consisted of administration of intravenous boluses of fentanyl, 50 µg according to the attending anesthesiologist's decision. At the end of surgery, muscle relaxation was reversed using neostigmine 0.05 mg / kg and atropine 0.01 mg / kg.

Patients will receive placebo tablet 2 hour before operation and will be anesthetized by combined spinal-general anesthesia that includes: spinal anesthesia with morphine 0.3 mg delivered in L4-5 inter spinous space. General anethseia: Induction of anesthesia was done by intravenous fentanyl, 2 µg / kg and propofol 1 - 2 mg / kg. Endotracheal intubation was achieved by cis-atracurium, 0.15 mg / kg. Maintenance of anesthesia was done by isoflurane and cis-atracurium, 0.03 mg / kg on demand. Additional intraoperative analgesia was consisted of administration of intravenous boluses of fentanyl, 50 µg according to the attending anesthesiologist's decision. At the end of surgery, muscle relaxation was reversed using neostigmine 0.05 mg / kg and atropine 0.01 mg / kg.

Inclusion Criteria: adult patients, subjected to major abdominal cancer surgery Exclusion Criteria: patients on chronic opioid therapy patients allergic to study drugs (duloxetine+morphine) patients have uncontrolled hypertension and or ischemic heart disease