a Small Dose of Naloxone,Minimize Intrathecal Morphine Side Effects
Condition: Post-Op Complication
MeSH terms: Postoperative Complications
Study type: Interventional

Summary: 
      I.V naloxone decreases incidence and severity of the common morphine side effects (pruritis,
      nausea/emesis, constipation, urinary retention, respiratory depression and undesirable
      sedation) so using it as additive to intrathecal morphine in patients undergoing anal
      surgeries under spinal anesthesia may be beneficail
    

Detailed description: 
      Bupivacaine hydrochloride is a commonly used local anesthetic in spinal anesthesia, however,
      the duration of spinal analgesia by bupivacaine is limited to about 75-150 minutes,
      therefore, various additives have been used along with bupivacaine for the prolongation of
      its effect, to improve the quality of analgesia, and to minimize the requirement for
      postoperative analgesics .

      Opioids may be added to local anesthetic solutions to enhance surgical anesthesia and provide
      postoperative analgesia . This effect is mediated at the dorsal horn of the spinal cord,
      where opioids mimic the effect of endogenous enkephalins. The use of intrathecal (IT)
      morphine (0.1 to 0.5 mg) can provide effective control of postoperative pain for roughly 24
      hours . However, the use of IT morphine may result in serious side effects e.g. pruritus 53%,
      nausea and vomiting 43%.urinary retention 43% and delayed respiratory depression . These side
      effects may lead to patient discomfort and prolonged hospital stay thus limiting the
      usefulness of IT morphine.

      Naloxone has an extremely high affinity for μ-opioid receptors in the central nervous system
      (CNS). Naloxone is a μ-opioid receptor (MOR) competitive antagonist, and its rapid blockade
      of those receptors often produces rapid onset of withdrawal symptoms. Naloxone also has an
      antagonist action, though with a lower affinity, at κ- (KOR) and δ-opioid receptors (DOR).
      Unlike other opioid receptor antagonists, naloxone is essentially a pure antagonist with no
      agonist properties.

      I.V naloxone decreases incidence and severity of the common morphine side effects (pruritis,
      nausea/emesis, constipation, urinary retention, respiratory depression and undesirable
      sedation) The addition of naloxone to morphine decreases the opioid related side effects
      without affection of postoperative analgesia. This combination can be used for the treatment
      of severe refractory chronic low back pain.
    

Intervention name(s): Morphine; Morphine-Naloxone
Intervention type(s): Drug; Drug
Intervention description(s): 50 patients of this group will receive 5 mg of 0.5% hyperbaric bupivacaine with 0.2 mg morphine in 0.5 ml volume plus 0.5 ml as placebo (total volume 2 mL); 50 patients of this group will receive 5 mg of 0.5% hyperbaric bupivacaine with 0.2 mg morphine in 0.5 ml volume plus 5ng\ kg naloxone in 0.5 ml volume (total volume 2mL).
Intervention MeSH terms: Morphine; Naloxone
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment