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Intravenous Acetaminophen May Not Lower Opioid Use in Spine Patients

Intravenous acetaminophen may not decrease opioid utilization or lower opioid-related risks in the postoperative setting – a key argument against its routine inclusion in analgesic regimens, according to a study published in Anesthesia and Analgesia.

In pill form, acetaminophen is a common over-the-counter medication used to treat minor aches and pains. Its intravenous use, however,  was only relatively recently approved by the FDA in 2010, explained principal investigator Stavros G. Memtsoudis, MD, PhD, anesthesiologist and senior scientist at Hospital for Special Surgery (HSS).

Since its approval, intravenous acetaminophen use has been widely adopted as part of a multimodal analgesic approach meant to lower overall opioid consumption and decrease adverse outcomes associated with those medications.  It is also an expensive drug, adds Dr. Memtsoudis, who previously published research into its pricing in a 2015 issue of Regional Anesthesiologists and Pain Medicine. Additionally, there is not much data to back up the efficacy of intravenous acetaminophen in treating acute pain caused by orthopedic procedures in comparison to other more established and less costly alternatives.

These factors –  the limited data demonstrating its analgesic effectiveness, its high cost and its rapidly expanding use – spurred the researchers to investigate the impact intravenous acetaminophen has on postoperative pain control specifically in spine surgeries that have traditionally required high opioid use to treat postoperative pain.

Using data from 117,269 lumbar/lumbosacral spinal fusion patients enrolled in the Premier Healthcare Database from 2011 through 2014, the investigators evaluated an association between intravenous acetaminophen use with opioid use and opioid-related complications in surgeries that usually require a high dose of opioid medication.

The research team found that in 19 percent (n=22,208) of cases, at least one dose of intravenous acetaminophen was used.  Although the scientists did find a link between intravenous acetaminophen use on postoperative day 0 and 1 and opioid use, length of stay, and cost of hospitalization, the association did not coincide with a consistent pattern of significantly reducing the odds for complications, explains Crispiana Cozowicz, co-author and perioperative research fellow within the Department of Anesthesiology, Critical Care and Pain Medicine at HSS. When compared with the outcomes seen in administering other nonopioid analgesics - pregabalin/gabapentin, specifically – the impact of intravenous acetaminophen was minimal at best.

"We could not show that perioperative intravenous acetaminophen reduces inpatient opioid prescriptions and subsequently reduced odds for adverse outcomes," says Dr. Memtsoudis. "It remains to be determined if and under what circumstances intravenous acetaminophen has a meaningful clinical role in everyday practice."