Intravenous Acetaminophen to Reduce Post-operative Opioid Consumption (ACETAPOP)

Evaluating the Impact of IV Acetaminophen on Opioid Consumption in the Postoperative Period in Patients Undergoing Abdominal Surgery

Acetaminophen (Tylenol) is a commonly used medication after surgery to control pain. Tablets for oral use and suppositories for rectal use are the most frequently employed forms of acetaminophen after surgery. Intravenous (IV) acetaminophen is widely used in several countries but is not a standard medication for the adult population in Canada. It is mainly considered when it is impossible to take medication in tablet or suppository form. Opioids (Morphine, Hydromorphone, Oxycodone, etc.) are another class of medications commonly used after surgery for pain management. While they are generally very effective and stronger than acetaminophen or other pain relievers (e.g., ibuprofen/Advil), reducing their use is preferable, as they can cause various side effects such as nausea, dizziness, and dependence. IV acetaminophen may help control pain while also reducing opioid consumption. However, there are few high-quality scientific studies proving the benefits of IV acetaminophen compared to other forms, such as tablets or suppositories. Acetaminophen has been available in Canada for many years and has already been recommended for use in Quebec by the Institut national d'excellence en santé et services sociaux (INESSS) under certain conditions. This study aims to validate its benefits with clear data.

Study Overview

• Status: Not yet recruiting
• Conditions: Epidural Analgesia; Pain Management; Post Operative Nausea and Vomiting; Post Operative Analgesia; Mobility; Length of Stay; Acetaminophen; Post Operative Bowel Dysfunction; Post Operative Pain Control; Abdominal Surgeries; Opioid Consumption, Postoperative
• Intervention / Treatment: Drug: IV Acetaminophen

Detailed Description

In 2019, the Institut national d'excellence en santé et services sociaux (INESSS) stated that IV acetaminophen is an acceptable short-term pain treatment option in combination with opioid analgesics for adults and children aged two years and older when oral (PO) and rectal (IR) acetaminophen cannot be used. Despite this recommendation, there is limited data on IV acetaminophen in patients with a compromised enteral route, even though this is likely one of the populations that could benefit the most from such an intervention. Patients undergoing abdominal surgeries are a prominent example of individuals with a compromised enteral route. Some data exist for other types of surgeries, such as orthopedic surgery. However, such data is challenging to extrapolate to abdominal surgeries since orthopedic surgery does not affect the digestive system. Furthermore, several studies use comparators that do not accurately reflect clinical practice, such as placebo. This study will therefore use standard treatment as a comparator, allowing for a better assessment of IV acetaminophen's role in the therapeutic arsenal.

IV acetaminophen is approved and marketed in Canada. It is not an investigational product. Furthermore, it is currently used in other hospital centers and has already been used at the Centre hospitalier de l'Université de Montréal (CHUM). Given current budgetary limitations, PO and IR formulations of acetaminophen have been preferred over the IV formulation, as their economic burden is less than IV acetaminophen.

Currently, pharmacists play a central role in the healthcare system as medication experts and key players in patient care in both community and hospital settings. Over the years, pharmacists in Québec have also become prescribers by law. They are valuable allies in hospitals, ensuring proper treatment follow-up and continuously validating that pharmacological care standards for patients of the CHUM are met.

The research question is as follows: Compared to standard local postoperative treatment, does IV acetaminophen reduce the amount of opioids administered within the first 72 postoperative hours in patients with a compromised enteral route in the abdominal surgery units of a Québec university hospital center?

• Study Type: Interventional
• Enrollment (Estimated): 140
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Suhail Sami Jouni, BSc, PharmD, MSc; Phone Number: 36163 514-890-8000; Email: suhail.sami.jouni.chum@ssss.gouv.qc.ca
• Study Contact Backup: Name: Thierry Nader, PharmD, MSc candidate; Phone Number: 36163 514-890-8000; Email: thierry.nader.chum@ssss.gouv.qc.ca

Study Locations

• Canada
  • Quebec
    • Montréal, Quebec, Canada, H2X 0A9
      • Centre Hospitalier de l'Universite de Montreal
      • Contact: Suhail Sami Vandenbroucke-Menu, MD; Phone Number: 36163 514-890-8000; Email: suhail.sami.jouni.chum@ssss.gouv.qc.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older.
• Underwent abdominal surgery
• Underwent elective surgery.
• Hospitalized in the digestive surgery, hepatobiliary and pancreatic surgery, or gynecology and gynecologic oncology units at CHUM.
• Declared NPO immediately post-surgery, meaning they cannot take oral medications.

Exclusion Criteria:

• Hypersensitivity to acetaminophen or an excipient in the administered formulations
• Hepatic insufficiency with a Child-Turcotte-Pugh score of B or C.
• Weight < 50 kg (patients requiring a lower acetaminophen dose).
• Active pregnancy or breastfeeding.
• Opioid use disorder (OUD) under active treatment
• Non-opioid-naïve patients: those who received a long-acting opioid within seven days preceding surgery. This criterion will be verified through patient interviews and cross-checked with medical records.
• Use of illicit recreational substances.
• Prior participation in this study.
• Ectopic patients: physically located in a unit other than digestive surgery (11 South), hepatobiliary and pancreatic surgery (14 South), or gynecology and gynecologic oncology (12 South).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Pre-intervention arm (standard protocol containing PO or IR Acetaminophen); This arm will receive the protocol currently used at the CHUM surgical units for post operative pain management, which includes PO or IR acetaminophen.
Active Comparator: Post-intervention arm (modified protocol containing IV Acetaminophen); This arm will receive a modified protocol version of the one used at the CHUM surgical units for post operative pain management, which includes IV acetaminophen.	Drug: IV Acetaminophen; This intervention will be administered to patients undergoing abdominal surgery who are nil per os (NPO) directly after surgery. This patient group has not been properly studied in other clinical studies using IV Acetaminophen. The study aim is to determine if patients who have an altered enteral route may benefit from IV Acetaminophen.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid consumption in oral morphine milligram equivalents (MME)	To determine whether the systematic use of IV acetaminophen in adult NPO patients in the postoperative context of abdominal surgery (post-intervention) reduces the average opioid consumption in oral morphine milligram equivalents (MME) over 72 hours compared to the standard protocol, which includes PO or IR acetaminophen (pre-intervention).	72 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid consumption (converted to MME) at 24 and 48 hours postoperatively	To determine whether the systematic use of IV acetaminophen reduces the average opioid consumption in MME over the first 24 and 48 postoperative hours in the post-intervention period compared to the pre-intervention period.	48 hours

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain level at rest (on a scale from 0 to 10) during the first 72 hours.	Compare the variation in resting pain levels during the periods of 0 to 24 hours, 24 to 48 hours, 0 to 48 hours, 48 to 72 hours, and 0 to 72 hours between the pre-intervention and post-intervention periods. This simple scale asks patients to rate their pain on a scale from zero (no pain) to ten (maximum pain).	72 hours
Pain level during mobilization (on a scale from 0 to 10) during the first 72 hours	Compare the average pain level during mobilization (upon standing) on postoperative days 0, 1, and 2 between the pre-intervention and post-intervention periods. This simple scale asks patients to rate their pain on a scale from zero (no pain) to ten (maximum pain)	72 hours
Length of hospital stay	Compare the length of hospital stay in days from the end of surgery until hospital discharge between the pre-intervention and post-intervention periods.	From date of the abdominal surgery until the date of hospital discharge, assessed up to 6 months
Nausea and constipation (antiemetic doses, laxative use)	Compare the frequency of nausea and constipation between the pre-intervention and post-intervention periods	72 hours
Functionality: time to first mobilization, mean chair time on postoperative days 1 and 2, time to return of oral intake, time to epidural discontinuation.	Compare the average time (in days) before the return of an uncompromised enteral route, complete epidural weaning, and first mobilization (first time standing up) between the pre-intervention and post-intervention periods. Compare the average time spent seated in a chair on postoperative days 1 and 2 between the pre-intervention and post-intervention periods.	72 hours

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)
• Investigators: Principal Investigator: Franck Vandenbroucke-Menu, MD, Centre Hospitalier de l'Universite de Montreal (CHUM)

Study record dates

Study Major Dates

• Study Start (Estimated): April 28, 2025
• Primary Completion (Estimated): August 15, 2025
• Study Completion (Estimated): August 15, 2025

Study Registration Dates

• First Submitted: March 13, 2025
• First Submitted That Met QC Criteria: April 4, 2025
• First Posted (Actual): April 11, 2025

Study Record Updates

• Last Update Posted (Actual): April 11, 2025
• Last Update Submitted That Met QC Criteria: April 4, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: acetaminophen; pancreatic surgery; post operative pain; gynecologic surgery; post operative analgesia; opioid consumption; abdominal surgery; post operative nausea and vomiting; intravenous acetaminophen; IV acetaminophen; nil per os; npo; hepato-biliary surgery; digestive surgery; post operative mobility; hospitalization length of stay; co-analgesia
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Signs and Symptoms, Digestive; Digestive System Diseases; Gastrointestinal Diseases; Neurobehavioral Manifestations; Perceptual Disorders; Pain, Postoperative; Nausea; Vomiting; Postoperative Nausea and Vomiting; Intestinal Diseases; Agnosia; Physiological Effects of Drugs; Peripheral Nervous System Agents; Sensory System Agents; Analgesics, Non-Narcotic; Analgesics; Antipyretics; Acetaminophen
• Other Study ID Numbers: 2025-12623

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No