Aminotransferase Trends During Prolonged Acetaminophen Dosing

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00743093
Recruitment Status : Completed
First Posted : August 28, 2008
Results First Posted : July 25, 2013
Last Update Posted : September 18, 2013
McNeil Consumer & Specialty Pharmaceuticals, a Division of McNeil-PPC, Inc.
Information provided by (Responsible Party):
Kennon Heard, Denver Health and Hospital Authority

Study Type: Interventional
Study Design: Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Conditions: Drug Toxicity
Interventions: Drug: acetaminophen
Drug: placebo

  Participant Flow

Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Recruitment took place from August 2008 through August 2011 in the Denver Metro area. Healthy volunteers were recruited from the community through the use of approved advertisements.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
398 subjects were consented for the study. Of these, 122 were excluded for not meeting full eligibility criteria. 276 eligible subjects were assigned to treatment groups, of which 252 completed all study requirements.

Reporting Groups
Acetaminophen Arm


acetaminophen : 500 mg caplets; 2 capsules (1 g)/dose; 4 doses (4 g)/day, 4 hours apart for 16 to 40 days.

Placebo Arm


placebo : placebo caplets, 2 caplets per dose, 4 doses per day, 4 hours apart for 16 to 40 days

Participant Flow for 2 periods

Period 1:   Base Study Period
    Acetaminophen Arm   Placebo Arm
STARTED   224   52 
COMPLETED   205   47 

Period 2:   Extended Dosing Period
    Acetaminophen Arm   Placebo Arm
STARTED   51 [1]   1 [1] 
COMPLETED   48   1 
[1] Subjects not meeting stopping criteria after base continued into the extended dosing.

  Baseline Characteristics

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
Baseline characteristics were collected on all subjects at screening and included: race, ethnicity, gender, age, weight, and height. The number of participants included in the analysis (276) is based on the safety population, which includes any subject that took at least one dose of study medication.

Reporting Groups
Acetaminophen Arm acetaminophen 500 mg
Placebo Arm placebo
Total Total of all reporting groups

Baseline Measures
   Acetaminophen Arm   Placebo Arm   Total 
Overall Participants Analyzed 
[Units: Participants]
 224   52   276 
[Units: Participants]
<=18 years   1   0   1 
Between 18 and 65 years   221   52   273 
>=65 years   2   0   2 
[Units: Years]
Mean (Standard Deviation)
 36.3  (12.16)   35.8  (12.50)   36.2  (12.21) 
[Units: Participants]
Female   163   39   202 
Male   61   13   74 
Region of Enrollment 
[Units: Participants]
United States   224   52   276 

  Outcome Measures

1.  Primary:   The Proportion of Subjects Treated With Long-term Acetaminophen (4 g/Day) That Develops Persistent ALT Elevations.   [ Time Frame: serial samples for 16-40 days ]

2.  Secondary:   The Proportion of Subjects With Detectable Serum Acetaminophen-cysteine Adduct (APAP-cys) Concentrations 1, 2, and 3 Days After Starting the Maximal Recommended Dosing of Acetaminophen (4 g/Day).   [ Time Frame: Days 1-3 ]

  Serious Adverse Events

  Other Adverse Events

  Limitations and Caveats

Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
This study was limited to healthy volunteers. The ingestion of each dose of study drug and use of other medications was self-reported.

  More Information

Certain Agreements:  
All Principal Investigators ARE employed by the organization sponsoring the study.

Results Point of Contact:  
Name/Title: Jody Green, PhD
Organization: Denver Heatlh Rocky Mountain Poison and Drug Center
phone: 303-389-1246

Publications automatically indexed to this study by Identifier (NCT Number):

Responsible Party: Kennon Heard, Denver Health and Hospital Authority Identifier: NCT00743093     History of Changes
Other Study ID Numbers: COMIRB #06-1265
First Submitted: August 26, 2008
First Posted: August 28, 2008
Results First Submitted: March 18, 2013
Results First Posted: July 25, 2013
Last Update Posted: September 18, 2013