Trial Outcomes & Findings for Oral Acetaminophen for Post-Op Pain Management in Bariatric Surgery Patients (NCT NCT06658574)

Last Updated: 2026-08-24

Results Overview

Numeric Pain Score (The scale has a fixed range with 0 representing "no pain" and the upper limit of 10 representing "worst pain possible"). A single numeric pain score is shown as an average of multiple combined time points.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

65 participants

Primary outcome timeframe

From date of consent until the date of hospital discharge, assessed up to 3 months.

Results posted on

2026-08-24

Participant Flow

The clinical coordinator of the bariatric surgery program recruited patients during the pre-operative admission process between November 2024 and May 2025. The first participant was enrolled on November 13, 2024, and the last on May 2, 2025.

Of 88 participants screened, 65 met the inclusion criteria and were randomized to treatment.

Participant milestones

Participant milestones
Measure	Oral Acetaminophen - Tablet Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Overall Study STARTED	33	32
Overall Study COMPLETED	17	18
Overall Study NOT COMPLETED	16	14

Reasons for withdrawal

Reasons for withdrawal
Measure	Oral Acetaminophen - Tablet Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Overall Study Protocol Violation	15	13
Overall Study Withdrawal by Subject	1	0
Overall Study Physician Decision	0	1

Baseline Characteristics

Oral Acetaminophen for Post-Op Pain Management in Bariatric Surgery Patients

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Oral Acetaminophen - Tablet n=33 Participants Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=32 Participants Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup	Total n=65 Participants Total of all reporting groups
Age, Continuous	43.0 years STANDARD_DEVIATION 12.3 • n=1541 Participants	40.4 years STANDARD_DEVIATION 10.7 • n=1121 Participants	41.7 years STANDARD_DEVIATION 11.5 • n=2662 Participants
Sex: Female, Male Female	26 Participants n=1541 Participants	27 Participants n=1121 Participants	53 Participants n=2662 Participants
Sex: Female, Male Male	7 Participants n=1541 Participants	5 Participants n=1121 Participants	12 Participants n=2662 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	12 Participants n=1541 Participants	9 Participants n=1121 Participants	21 Participants n=2662 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	21 Participants n=1541 Participants	22 Participants n=1121 Participants	43 Participants n=2662 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=1541 Participants	1 Participants n=1121 Participants	1 Participants n=2662 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=1541 Participants	0 Participants n=1121 Participants	0 Participants n=2662 Participants
Race (NIH/OMB) Asian	2 Participants n=1541 Participants	1 Participants n=1121 Participants	3 Participants n=2662 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=1541 Participants	0 Participants n=1121 Participants	0 Participants n=2662 Participants
Race (NIH/OMB) Black or African American	7 Participants n=1541 Participants	6 Participants n=1121 Participants	13 Participants n=2662 Participants
Race (NIH/OMB) White	14 Participants n=1541 Participants	12 Participants n=1121 Participants	26 Participants n=2662 Participants
Race (NIH/OMB) More than one race	0 Participants n=1541 Participants	1 Participants n=1121 Participants	1 Participants n=2662 Participants
Race (NIH/OMB) Unknown or Not Reported	10 Participants n=1541 Participants	12 Participants n=1121 Participants	22 Participants n=2662 Participants
Height (cm)	163.6 centimeters STANDARD_DEVIATION 8.2 • n=1541 Participants	164.8 centimeters STANDARD_DEVIATION 7.0 • n=1121 Participants	164.2 centimeters STANDARD_DEVIATION 7.6 • n=2662 Participants
Weight (kg)	114.5 kilograms STANDARD_DEVIATION 31.2 • n=1541 Participants	123.3 kilograms STANDARD_DEVIATION 31.2 • n=1121 Participants	118.9 kilograms STANDARD_DEVIATION 31.2 • n=2662 Participants
BMI	44.4 kg/m2 STANDARD_DEVIATION 14.3 • n=1541 Participants	44.8 kg/m2 STANDARD_DEVIATION 9.8 • n=1121 Participants	44.6 kg/m2 STANDARD_DEVIATION 12.2 • n=2662 Participants
Comorbidities None	6 Participants n=1541 Participants	7 Participants n=1121 Participants	13 Participants n=2662 Participants
Comorbidities Type 2 Diabetes Mellitus	3 Participants n=1541 Participants	3 Participants n=1121 Participants	6 Participants n=2662 Participants
Comorbidities Hypertension	6 Participants n=1541 Participants	7 Participants n=1121 Participants	13 Participants n=2662 Participants
Comorbidities Dyslipidemia	9 Participants n=1541 Participants	10 Participants n=1121 Participants	19 Participants n=2662 Participants
Comorbidities Cardiovascular Disease	1 Participants n=1541 Participants	1 Participants n=1121 Participants	2 Participants n=2662 Participants
Comorbidities Obstructive Sleep Apnea	2 Participants n=1541 Participants	4 Participants n=1121 Participants	6 Participants n=2662 Participants
Comorbidities Gastroesophageal Reflux Disease (GERD)	6 Participants n=1541 Participants	2 Participants n=1121 Participants	8 Participants n=2662 Participants
Comorbidities Osteoarthritis	3 Participants n=1541 Participants	0 Participants n=1121 Participants	3 Participants n=2662 Participants
Comorbidities Non-alcoholic Fatty Liver Disease	2 Participants n=1541 Participants	3 Participants n=1121 Participants	5 Participants n=2662 Participants
Comorbidities Chronic Kidney Disease	2 Participants n=1541 Participants	1 Participants n=1121 Participants	3 Participants n=2662 Participants
Comorbidities Gallbladder Disease	1 Participants n=1541 Participants	0 Participants n=1121 Participants	1 Participants n=2662 Participants
Comorbidities Depression and Anxiety Disorders	4 Participants n=1541 Participants	4 Participants n=1121 Participants	8 Participants n=2662 Participants
Comorbidities Polycystic Ovary Syndrome (PCOS)	1 Participants n=1541 Participants	1 Participants n=1121 Participants	2 Participants n=2662 Participants
Comorbidities Asthma and Other Respiratory Disorders	3 Participants n=1541 Participants	3 Participants n=1121 Participants	6 Participants n=2662 Participants
Comorbidities Cancer	3 Participants n=1541 Participants	0 Participants n=1121 Participants	3 Participants n=2662 Participants
Comorbidities Venous Thromboembolism	1 Participants n=1541 Participants	0 Participants n=1121 Participants	1 Participants n=2662 Participants
Comorbidities Other	9 Participants n=1541 Participants	6 Participants n=1121 Participants	15 Participants n=2662 Participants

PRIMARY outcome

Timeframe: From date of consent until the date of hospital discharge, assessed up to 3 months.

Outcome measures

Outcome measures
Measure	Oral Acetaminophen - Tablet n=17 Participants Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=18 Participants Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Pain Control	3.8 Units on a scale (0 to 10) Standard Deviation 1.5	3.6 Units on a scale (0 to 10) Standard Deviation 1.3

SECONDARY outcome

Timeframe: From date of consent until the date of hospital discharge, assessed up to 3 months

Participants' length of hospital stay in days.

Outcome measures

Outcome measures
Measure	Oral Acetaminophen - Tablet n=17 Participants Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=18 Participants Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Length of Stay (LOS)	1.3 Days Standard Deviation 0.5	1.3 Days Standard Deviation 0.3

SECONDARY outcome

Timeframe: From date of consent until the date of hospital discharge, assessed up to 3 months

The Milligrams Morphine Equivalents (MME) value represents the potency of an opioid dose relative to morphine. The single MME value is an average across multiple combined time points.

Outcome measures

Outcome measures
Measure	Oral Acetaminophen - Tablet n=17 Participants Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=18 Participants Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Milligrams Morphine Equivalents (MME)	6.1 Morphine Milligram Equivalents (MME) Standard Deviation 7.5	4.1 Morphine Milligram Equivalents (MME) Standard Deviation 5.7

SECONDARY outcome

Timeframe: The time, in hours, from the completion of surgery to the time of oral intake.

The amount of time in hours from surgery completion to oral intake documented in the subjects' electronic health record.

Outcome measures

Outcome measures
Measure	Oral Acetaminophen - Tablet n=17 Participants Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=18 Participants Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Time From Surgery to Oral Intake	7.4 Hours Standard Deviation 4.8	7.8 Hours Standard Deviation 8.1

Adverse Events

Oral Acetaminophen - Tablet

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Oral Acetaminophen - Liquid

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Oral Acetaminophen - Tablet n=17 participants at risk Acetaminophen 650 mg tablet by mouth Arm 1: Once cleared for oral intake - acetaminophen tablets 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days\' dispensed as unit-dose tablets	Oral Acetaminophen - Liquid n=18 participants at risk Acetaminophen 650 mg liquid by mouth Arm 2: Once cleared for oral intake - acetaminophen liquid (160 mg/5 mL) 650 mg PO every 6 hours PRN - mild pain (1 - 3) to a maximum of 4 grams daily for 3 days; 650 mg = 20.3 mL, dispensed as a unit-dose cup
Gastrointestinal disorders Nausea	0.00% 0/17 • From hospital admission to discharge. The risks to subjects in this study were minimal. While rare, there is a risk for hypersensitivity or other intolerance to acetaminophen or any of the inactive ingredients in the formulation. However, every patient enrolled was screened for a known hypersensitivity or history of intolerance to acetaminophen or any inactive ingredients in both the oral and liquid formulations.	5.6% 1/18 • Number of events 1 • From hospital admission to discharge. The risks to subjects in this study were minimal. While rare, there is a risk for hypersensitivity or other intolerance to acetaminophen or any of the inactive ingredients in the formulation. However, every patient enrolled was screened for a known hypersensitivity or history of intolerance to acetaminophen or any inactive ingredients in both the oral and liquid formulations.

Additional Information

Daniel Abazia, PharmD

Ernest Mario School of Pharmacy - Rutgers, The State University of New Jersey

Phone: 773-633-5215

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place