IV acetaminophen: Efficacy of a single dose for postoperative pain after hip arthroplasty: subset data analysis of 2 unpublished randomized clinical trials

Abstract

Inadequate control of postoperative pain after orthopedic procedures may trigger complications that increase morbidity. Multimodal analgesia is used to manage pain effectively after surgical procedures and reduce the need for rescue analgesia. Intravenous (IV) acetaminophen (OFIRMEV; Cadence Pharmaceuticals, Inc.), an analgesic that has been studied and used in the multimodal management of acute pain after major orthopedic procedures, combines the safety seen with oral and rectal formulations with a preferred route of administration. Two double-blind, randomized, placebo-controlled clinical trials were conducted (total 130 patients) to determine the efficacy and safety of single-dose IV acetaminophen in patients following total hip arthroplasty. Although both studies were stopped prematurely, overlap in patient populations, study design, and methodologies in the single-dose phase of these studies allowed for analysis of their results to be presented concurrently. Both trials demonstrated IV acetaminophen having greater efficacy than placebo in terms of primary endpoints [pain intensity differences from T0.5 to T3 (P < 0.05 in both studies)]. The use of IV acetaminophen also reduced the need for rescue opioid consumption, with patients receiving IV acetaminophen consuming, on average, less than half the amount of rescue medication as those receiving placebo. IV acetaminophen was effective in treating moderate-to-severe pain after total hip arthroplasty and reduced the need for rescue opioid consumption.