“…Although the relationship between the occurrence of pruritus and the dose of fentanyl is not sufficiently evident, it has been a frequent complaint among patients who received this drug intrathecally. 1 , 6 , 10 , 11 , 12 , 13 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 Approximately 80% of patients receiving fat-soluble opioid intrathecally report pruritus, which in some cases is described as severe and stressful. 27 , 28 , 29 , 30 In this study, the occurrence of pruritus was similar in the groups receiving different doses of fentanyl, therefore, it was not a dose-dependent effect as described by many authors.…”