Fentanyl pretreatment for alleviation of perineal symptoms following preoperative administration of intravenous dexamethasone sodium phosphate: A prospective, randomized, double blind, placebo controlled study

Background: Corticosteroids have anti-inflammatory, analgesic and antiemetic effects but causes severe perineal symptoms when given intravenously. Simultaneous administration of dexamethasone and fentanyl have been known to decrease the duration of perineal pain but its role in alleviating perineal pain has not been studied. Therefore, we hypothesized that fentanyl pretreatment could prevent the perineal symptoms associated with the dexamethasone. Material and Methods: This prospective, randomized, double blind, placebo controlled study was done in 200 patients undergoing elective surgery requiring dexamethasone. The patients were randomized into two groups of 100 each. Group BD received 5 ml normal saline followed, 5 minutes later, by 8 mg dexamethasone bolus intravenously. Group FD received 1 μg/kg fentanyl diluted in saline to a volume of 5 ml followed by 8 mg dexamethasone bolus 5 minutes later. The time of onset, intensity, site, duration and nature of the pain after the drug administration were recorded. Results: The demographic profile was comparable in the two groups. The incidence and severity of pain was more in females as compared to males (p value = 0). The pain was located especially in the perineal region and was expressed as itching (62%), burning (13%) or both (25%). The incidence of pain, its duration and severity were significantly reduced after pretreatment with fentanyl (p value = 0). Discussion: Our study showed that the intravenous administration of dexamethasone sodium phosphate leads to significant perineal symptoms. These symptoms are alleviated by pretreatment with fentanyl (1 μg/kg) (incidence, severity and duration). The pharmacological mechanism explaining perineal pain with intravenous administration of dexamethasone remains poorly understood, but could be related to the phosphate ester.