A comparison of tramadol, amitriptyline, and meperidine for postepidural anesthetic shivering in parturients

Tramadol is effective for treating shivering during epidural anesthesia in parturients. In addition to its low affinity to opioid receptors, tramadol exerts a modulatory effect on central monoaminergic pathways. In this respe ct, there are parallels between the mechanisms of the action of tramadol an d antidepressants such as amitriptyline. Meperidine is often recommended fo r the treatment of postanesthetic shivering. This prospective, double-blind ed, and randomized clinical study was performed to compare the antishiverin g effects and accompanying side effects among tramadol, meperidine, and ami triptyline for the treatment of postepidural anesthetic shivering. Forty-fi ve parturients who shivered during cesarean delivery under epidural anesthe sia and requested antishivering treatment were randomly allocated to one of three groups for IV treatment: Group T (n = 15) received tramadol 0.5 mg/k g, Group M (n = 15) received meperidine 0.5 mg/kg, and Group A (n = 15) rec eived amitriptyline 15 or 20 mg. The response rate (shivering ceased after treatment in 15 min) was 87% and 93% for Groups T and M, respectively, comp ared with 13% in Group A (P < 0.01). The time that elapsed from treatment t o the time shivering ceased was 5.1 +/- 3.6 min (mean SD) for Group T and 4 .2 +/- 2.3 min for Group M. There was a significantly more frequent inciden ce (33%) of somnolence in Group M when compared with Groups T (7%) and A (0 %) (P < 0.01). However, no significant differences were shown for pruritus, nausea, vomiting, or Apgar scores of newborns. We concluded that both tram adol and meperidine show a significantly faster response rate in the treatm ent of postepidural anesthetic shivering when compared with amitriptyline i n the dosage used; tramadol had a decreased incidence of somnolence when co mpared with meperidine.