The authors of a study examining a comprehensive opioid-sparing multimodal analgesia approach found that patients in both IV and oral acetaminophen groups scored low on pain scales, limited opioid usage, and reported minimal opioid side effects. There was no difference between groups.1

“We have a multimodal low opioid protocol that we’ve refined over many years for total hip replacement,” says Geoffrey Westrich, MD, director of research for the adult reconstruction and joint replacement service at the Hospital for Special Surgery (HSS) in New York City. “That’s our starting point, and that’s critical because when we discuss findings, you can’t decide that IV acetaminophen doesn’t work. The patient satisfaction was 9.0 and 9.1 out of 10 in both groups of IV and oral acetaminophen.”

The double-blinded, randomized, controlled trial included 154 hip replacement surgery patients who received either IV or oral acetaminophen as part of the standard multifaceted pain control protocol postsurgery. The patients who were given IV acetaminophen also received a placebo in pill form. The other group of patients received the opposite: acetaminophen pill and IV placebo.1

Researchers expected to find that IV acetaminophen would reduce pain with activity, opioid usage, and opioid-related side effects when compared with oral acetaminophen. “The oral acetaminophen worked as well as IV at our hospital with our multimodal pain management, low-opioid protocol,” Westrich reports. “You can’t tell other hospitals not to use the IV form because if they use other protocols, then IV forms might work better for them.”

HSS still uses IV medication in knee and spine surgery. “Some patients are nauseous and can’t take oral medication. We use IV in the first 24 hours because we think it works well,” Westrich says.

“But based on our study, we wouldn’t use it in routine total hip surgeries.” The next step is to compare IV medication to oral medication in total knee replacement patients because they experience more pain postoperatively, Westrich says. “We think IV might be beneficial over oral for those patients,” he adds. “But that is to be determined.”

From an ambulatory surgery center (ASC) perspective, oral medication would work fine in many cases, Westrich says.

“If they are not following our protocol exactly, then they could benefit from using an IV form,” he says.


  1. Westrich GH, Birch GA, Muskat A, et al. Intravenous vs. oral acetaminophen as a component of multimodal analgesia after total hip arthroplasty: A randomized, blinded trial. J Arthroplasty 2019; Mar 6. pii: S0883-5403(19)30186-X. doi: 10.1016/j.arth.2019.02.030. [Epub ahead of print].