Background: Transsphenoidal pituitary surgery (TSS) is a neurosurgical procedure with mild to moderate postoperative pain, which is usually controlled by opioid analgesics. However, concerns about side effects associated with opioids have been challenges among these patients.  Thus, multimodal analgesics are often required to optimize pain control with less undesired effects.

Objective: Our study aimed to determine intravenous acetaminophen’s efficacy as an adjuvant therapy for postoperative pain management in TSS patients.

Methods: We conducted a prospective, double-blinded, randomized controlled trial.  Forty-six patients who had undergone elective TSS were recruited and randomly assigned to the acetaminophen or placebo group.  The total fentanyl consumptions in the first 24 hours were recorded. Pain scores and adverse effects such as nausea, vomiting, and sedation were recorded. All statistical analyses were performed using STATA 14.

Results: Based on the average pain scores, both groups received optimal postoperative pain management. Postoperative fentanyl consumption was 284.1±152.8 mcg in the study group and 364.4±211.7 mcg in the placebo group, respectively. Adding acetaminophen to fentanyl was associated with an opioid-sparing effect of 22% (P-value = 0.15) in the first 24 hours postoperative period. The incidences of nausea, vomit, sedation and respiratory depression were not different in both groups.

Conclusion: In our study, acetaminophen administration was not associated with a reduction of postoperative fentanyl consumption. Acetaminophen had neither significant fentanyl-sparing effects nor side effects reduction for postoperative pain management in TSS patients.