Author: Ajai Raj
The current use of IV acetaminophen (Ofirmev, Mallinckrodt) does not improve perioperative opioid utilization in open colectomy compared with the oral form of the drug, leading researchers to conclude that routine use of IV acetaminophen is not supported by the evidence for this procedure.
Published in Anesthesiology (2018;129:77-88), the study used national claims data from the Premier Healthcare Database (Premier Healthcare Solutions Inc. USA) for patients undergoing open colectomy from 2011 to 2016, encompassing 181,640 patient records from 602 hospitals across the United States. The effects of IV and oral acetaminophen use were measured separately, using the following categories for each:
The primary outcome of interest was opioid utilization throughout the hospital stay, and the secondary outcome assessed was opioid-related adverse effects.
A total of 25.1% of patients studied received IV acetaminophen, of whom 48.0% received a single dose on the day of surgery. In adjusted analyses, the researchers found that more than one dose of IV acetaminophen on postoperative day 1 was associated with a 12.4% decrease in opioid utilization compared with nonuse of the drug (99.5% CI, –15.2% to –9.4%). More than one oral dose on postoperative day 1, by contrast, was associated with a 22.6% decrease in opioid utilization (99.5% CI, –26.2% to –18.9%). All of the observed outcome patterns were statistically significant, but none were clinically significant, the researchers noted, adding that similar outcome patterns were observed with respect to opioid-related adverse events.
The researchers concluded that, given the availability of alternative nonopioid analgesic options, their findings do not support routine use of IV acetaminophen in this setting.
Commenting on the findings, author Stavros Memtsoudis, MD, PhD, the director of critical care services, a senior scientist and an attending anesthesiologist at the Hospital for Special Surgery, in New York City, said they are reflective of a widespread tendency to turn to any treatment that’s said to reduce opioid utilization and its side effects in the wake of the ongoing opioid crisis, regardless of whether the evidence is there to support it.
“The reality is that we are in such a frenzy to reduce opioid consumption and side effects that anything new that comes on the market and is thought to reduce opioid utilization, people are jumping on without having proper data,” Dr. Memtsoudis said. “Reducing opioids is certainly an important goal, and anything that can help with that is welcome. But IV acetaminophen, as it is currently used, doesn’t seem to have any benefits over oral administration, even in this population that may have limitations with oral intake since they’re undergoing surgery in their gastrointestinal tract.
“We also saw a surprising number of patients receiving IV acetaminophen in a relatively short period of time—over 25% of patients having this surgery,” he added. “That equates to a huge cost, as the IV formulation is much more expensive than the oral. And when you compare acetaminophen to traditional drugs like nonsteroidal anti-inflammatory drugs, those seem to be even better at reducing opioid consumption and side effects.
“So if we put all of it together, we see that IV acetaminophen is not the silver bullet everyone is looking for; on the contrary, it adds cost without necessarily adding value,” Dr. Memtsoudis said.
IV Acetaminophen for Some Surgeries Still Valid
Jashvant Poeran, MD, PhD, the director of the center for clinical and outcomes research at the Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, in New York City, and second author of the paper, added that the findings don’t mean that IV acetaminophen is never called for, but rather that further research needs to be done to identify those patients who stand to benefit from it.
“IV acetaminophen was approved by the Food and Drug Administration based on highly selective trials, but has subsequently gone on to be widely used in ways that don’t necessarily line up with those studies,” Dr. Poeran said. “So we wouldn’t say to never use the IV route, but we need to figure out how it can be used in the most effective way.”
Nabil Elkassabany, MD, MSCE, an associate professor and the director of the sections of regional and orthopedic anesthesiology at the University of Pennsylvania, in Philadelphia, said the findings were “almost expected, based on similar studies done in the past.” Also, the study “highlights the importance of clinical judgment and of individualizing treatment within clinical pathways and protocols.
“I would say that for some patients, such as those who can’t tolerate the oral form of acetaminophen, the IV route is going to be a no-brainer,” Dr. Elkassabany said. “We need to identify specific patient populations in which the IV route will add value.”
Dr. Elkassabany concurred with Drs. Memtsoudis and Poeran that overuse of IV acetaminophen is driven partly by what he called a “clinical hunger” for opioid-sparing approaches.
“Everyone’s loo king for a new technique or a new drug that will help reduce opioid utilization, whether it’s a technique, like a nerve block, or a niche formulation of a drug, as in the case of IV acetaminophen,” Dr. Elkassabany said. “The issue is that people are jumping on a bandwagon just because something is advertised as opioid-sparing, whether or not that’s been borne out in clinical trials or formal research studies.”