title: Comparison of mirtazapine, gabapentin and ondansetron to prevent intrathecal morphine-induced pruritus.
abstract: OBJECTIVE
  Antagonism of the central nervous system inhibitor neurotransmitter gamma-Aminobutyric acid (GABA) or serotonergic system activation is an important factor in the pathogenesis of intrathecal morphine-induced pruritus. This study tested the hypothesis that preoperative use of ondansetron, gabapentin or mirtazapine can prevent morphine-induced pruritus.
  
  
  METHODS
  We randomly allocated 80 patients of American Society of Anesthesiology (ASA) classification I and II physical status who were to undergo unilateral inguinal hernia or pilonidal sinus operations under spinal anesthesia into 4 equal groups. The first 3 groups received oral doses of 30 mg mirtazapine, 8 mg ondansetron, and 1200 mg gabapentin at 2 hours, 10 minutes, and 1 hour before surgery, respectively, and the fourth group was given a placebo. All patients received intrathecal injection of 15 mg of 0.5% hyperbaric bupivacaine and 0.2 mg morphine. Pruritus was evaluated at 0, 3, 6, 9, 12, and 24 hours after intrathecal morphine administration, and details of presence, onset time, duration, localization, and severity of pruritus were recorded.
  
  
  RESULTS
  Incidence of pruritus was significantly more frequent in the placebo group compared to ondansetron, gabapentin, and mirtazapine groups (70%, 55%, 35%, and 35%, respectively). In general, onset of pruritus was between 2 and 6 hours after intrathecal morphine injection; however, onset in the gabapentin group (mean±SD: 4.75±2.7 hours; p=0.019) was delayed compared to other groups. It was observed that pruritus persisted relatively longer in the ondansetron and placebo groups (mean±SD: 6±3.08; 5.82±2.96 hours, respectively; p=0.047). No statistical determination was made regarding location of pruritus. Severity of pruritus was greater in the placebo group (p=0.0001). Necessity for antipruritic treatment was not statistically significantly different between groups.
  
  
  CONCLUSIONS
  Incidence and severity of intrathecal morphine-induced pruritus decreased with use of each of all 3 drugs compared to placebo.
authors.affiliation: Department of Anesthesiology and Reanimation, Karabük Training and Research Hospital, Karabük, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Akhan
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Ferhunde Dilek
authors.initials: FD
authors.lastname: Subasi
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Gulsen
authors.initials: G
authors.lastname: Bosna
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Ekinci
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Pamuk
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Siddika
authors.initials: S
authors.lastname: Batan
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Rezzan Yagmur
authors.initials: RY
authors.lastname: Ateser
authors.affiliation: Department of Anesthesiology and Reanimation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey.
authors.forename: Gulden
authors.initials: G
authors.lastname: Turan
keywords: Gabapentin; intrathecal; mirtazapine; morphine; ondansetron; pruritus