Morbid ObesityPhase 4APAPNCT01764555
Pharmacokinetics of Acetaminophen in Morbidly Obese Patients
A Phase 4 study testing acetaminophen 2 g in people with Morbid Obesity, run by St. Antonius Hospital at 1 site in Netherlands.
Trial summary
This study will investigate the pharmacokinetics of acetaminophen in morbidly obese patients versus normal weight patients. Specifically the different metabolic pathways of acetaminophen in morbidly obese adults will be investigated; glucuronidation, sulphation and CYP2E1 (cytochrome P450 2E1) oxidation Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Morbid Obesity
- What is being tested?
- acetaminophen 2 g
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteNetherlands
- Study dates
- Dec 2012to Mar 2014
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- BMI > 40 kg/m2 undergoing bariatric surgery.
- Patients between 18 - 60 years old
- ASA physical classification of II or III
- All racial and ethnic groups will be included
- BMI between 18 and 25 kg/m2 undergoing general surgery
- Patients between 18 - 60 years old
- ASA (American Society of Anesthesiology) physical classification of I, II or III
- All racial and ethnic groups will be included
Who cannot join
- Renal insufficiency
- Liver disease
- Patients with Gilbert-Meulengracht syndrome
- Chronic alcohol intake or use of alcohol within last 72 hours
- Pregnancy or breastfeeding
- Patients who are treated with drugs know to affect CYP2E1 and UGT (UDP glucuronosyltransferase)
Show all 9Show fewer
- Diabetes mellitus type II patients
- Smoking
- Acetaminophen intake before the study (24 hours before study)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Pharmacokinetics of Intravenous Acetaminophen and Its Metabolites in Morbidly Obese Patients
This study will investigate the pharmacokinetics of acetaminophen in morbidly obese patients versus normal weight patients. Specifically the different metabolic pathways of acetaminophen in morbidly obese adults will be investigated; glucuronidation, sulphation and CYP2E1 (cytochrome P450 2E1) oxidation
- Conditions
- Morbid Obesity
- Being tested
- acetaminophen 2 g
- Medical subject headings
- Obesity, Morbid
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
acetaminophen 2 gDrug
| Study group | Role | What they receive |
|---|---|---|
| normal weight patients | Experimental | normal weight patients receiving acetaminophen 2 g instead of 1 g Receives: Drug: acetaminophen 2 g |
| mobidly obese patients | Experimental | morbidly obese patients receiving acetaminophen 2 g instead of 1 g Receives: Drug: acetaminophen 2 g |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clearance (total, glucuronidation, sulphation, CYP2E1 oxidation and unchanged) of acetaminophen in morbidly obese patients in comparison with normal weight patients.
Measured: 24 hours
Volume of distribution of acetaminophen in morbidly obese patients in comparison with normal weight patients.
Measured: 24 hours
Secondary outcomes (3)
Difference in clearance (total, glucuronidation, sulphation, CYP2E1 oxidation) of acetaminophen in morbidly obese patients at the time of bariatric surgery and at 0.5 - 2 year after bariatric surgery.
Measured: 8 hours
Difference in volume of distribution of acetaminophen in morbidly obese patients at the time of bariatric surgery and at 0.5 - 2 year after bariatric surgery.
Measured: 8 hours
Liver function tests in morbidly obese patients in comparison with normal weight patients.
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jan 2013 (estimated)
- Study startDec 2012
- Primary completionMar 2014
- Study completionMar 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Morbid ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 28 participants (actual)
Sponsor and investigators
- Lead sponsor
- St. Antonius Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Catherijne Knibbe, St. Antonius Hospital
- Investigators
- Catherijne Knibbe, Prof dr, Principal investigator, St. Antonius Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01764555
- Sponsor's protocol ID
- APAP study
- Other IDs
- 2012-000956-32
- Acronym
- APAP
- Status last verified
- Apr 2019
- First submitted
- 10 Dec 2012
- Last updated
- 5 Apr 2019
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Wu Y, Voller S, Goulooze SC, Allegaert K, Sherwin CMT, van Rongen A, W E Roofthooft D, Simons SHP, Tibboel D, Flint RB, van den Anker JN, Knibbe CAJ. A Novel Maturation Equation for Hepatic Clearance Across Preterm, Term Neonates, Children, and Adults: Application to Paracetamol and Its Metabolite. J Clin Pharmacol. 2025 Dec;65(12):1829-1843. doi: 10.1002/jcph.70080. Epub 2025 Sep 5.
PubMed 40910464
Study at a glance
From the registry record, last updated by the sponsor on 5 Apr 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pharmacokinetics of Intravenous Acetaminophen and Its Metabolites in Morbidly Obese Patients
- ClinicalTrials.gov ID
- NCT01764555
- Acronym / sponsor ID
- APAP / APAP study
- Conditions
- Morbid Obesity
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 28 participants (actual)
- Lead sponsor
- St. Antonius HospitalUniversity, hospital or other
- Study start
- Dec 2012
- Primary completion
- Mar 2014 (actual)
- Study completion
- Mar 2014 (actual)
- First posted
- 9 Jan 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will investigate the pharmacokinetics of acetaminophen in morbidly obese patients versus normal weight patients. Specifically the different metabolic pathways of acetaminophen in morbidly obese adults will be investigated; glucuronidation, sulphation and CYP2E1 (cytochrome P450 2E1) oxidation
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| normal weight patients | Experimental | Drug: acetaminophen 2 gnormal weight patients receiving acetaminophen 2 g instead of 1 g |
| mobidly obese patients | Experimental | Drug: acetaminophen 2 gmorbidly obese patients receiving acetaminophen 2 g instead of 1 g |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- BMI > 40 kg/m2 undergoing bariatric surgery.
- Patients between 18 - 60 years old
- ASA physical classification of II or III
- All racial and ethnic groups will be included
- BMI between 18 and 25 kg/m2 undergoing general surgery
Key exclusion criteria (9 listed)
- Renal insufficiency
- Liver disease
- Patients with Gilbert-Meulengracht syndrome
- Chronic alcohol intake or use of alcohol within last 72 hours
- Pregnancy or breastfeeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| acetaminophen 2 g | Drug | mobidly obese patients, normal weight patients |
Primary outcome
Clearance (total, glucuronidation, sulphation, CYP2E1 oxidation and unchanged) of acetaminophen in morbidly obese patients in comparison with normal weight patients.
Time frame: 24 hours
Volume of distribution of acetaminophen in morbidly obese patients in comparison with normal weight patients.
Time frame: 24 hours
3 secondary outcomes
Difference in clearance (total, glucuronidation, sulphation, CYP2E1 oxidation) of acetaminophen in morbidly obese patients at the time of bariatric surgery and at 0.5 - 2 year after bariatric surgery.
Time frame: 8 hours
Difference in volume of distribution of acetaminophen in morbidly obese patients at the time of bariatric surgery and at 0.5 - 2 year after bariatric surgery.
Time frame: 8 hours
Liver function tests in morbidly obese patients in comparison with normal weight patients.
Time frame: 24 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Apr 2019.
- Derived from this study: PubMed 40910464Wu Y, Voller S, Goulooze SC, Allegaert K, Sherwin CMT, van Rongen A, W E Roofthooft D, Simons SHP, Tibboel D, Flint RB, van den Anker JN, Knibbe CAJ. A Novel Maturation Equation for Hepatic Clearance Across Preterm, Term Neonates, Children, and Adults: Application to Paracetamol and Its Metabolite. J Clin Pharmacol. 2025 Dec;65(12):1829-1843. doi: 10.1002/jcph.70080. Epub 2025 Sep 5.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Catherijne Knibbe, Prof dr principal investigator
St. Antonius Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing acetaminophen 2 g in people with Morbid Obesity, run by St. Antonius Hospital at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Apr 2019. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Clearance (total, glucuronidation, sulphation, CYP2E1 oxidation and unchanged) of acetaminophen in morbidly obese patients in comparison with normal weight patients. (time frame: 24 hours). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01764555, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Apr 2019.