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Adjuvant Analgesic Effects of Low Dose Tramadol/Acetaminophen Combination After Open Gynaecological Surgery

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: NCT00942565
Recruitment Status : Completed
First Posted : July 21, 2009
Last Update Posted : February 1, 2013
Information provided by (Responsible Party):
Cheung Chi Wai, The University of Hong Kong

Brief Summary:

Patient experience moderate to severe pain after abdominal surgery. This post-operative pain can also contribute to complications such as respiratory impairment, cardiovascular events, ileus, sleep deprivation and mood disturbance. Opioid based patient-controlled analgesia (PCA) is commonly employed but opioids have the side effects such as respiratory depression, nausea and vomiting, sedation, pruritus and urinary retention. Bowel motility can also be affected. Consequently alternative or adjunct analgesic medications without these side-effects have been investigated in order to reduce opioid consumption.

Multimodal analgesia is a technique whereby a combination of analgesic drugs with different modes of action can be used to improve analgesia and decrease adverse effects by virtue of synergism. Postoperatively, with adjunctive analgesia, PCA morphine consumption as well as the side effects may be reduced. Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to be opioid sparing and decrease the adverse effects of PCA morphine. A recent review showed that acetaminophen combined with PCA could induce a significant opioid-sparing effect but the incidence of PCA morphine related side effects were not reduced.

It is common nowadays to give oral analgesic supplements to post-operative patients on PCA morphine. Tramadol, an analogue of codeine, is one of the choices. However, some of the patients cannot tolerate the side effects such as nausea, drowsiness, sweating, postural hypotension and dry mouth. Combination of tramadol 37.5 mg and acetaminophen 375 mg, which has been used successfully to treat post-operative pain, may improve analgesic response with better tolerability.

This study is to assess tramadol 37.5 mg and acetaminophen 375 mg combination on the efficacy of pain control, down stepping of morphine consumption and related adverse events with PCA use after open colorectal surgeries.


This study aims to compare and evaluate:

  • The efficacy of tramadol/acetaminophen combination on postoperative pain relief after lower abdominal surgeries
  • The effects of tramadol/acetaminophen combination on the consumption and the duration of PCA morphine use
  • The adverse effects related to this regimen
  • The effects on postoperative bowel function, tolerability of fluid and diet, ambulatory function, sleep, and duration of hospital stay
  • The overall satisfaction of the patients

Condition or disease Intervention/treatment Phase
Postoperative Pain Drug: tramadol/acetaminophen Drug: acetaminophen Phase 4

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 60 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Study Start Date : April 2007
Actual Primary Completion Date : October 2008
Actual Study Completion Date : December 2012

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Tramadol/acetaminophen
The tramadol and acetaminophen combination was given to patients at the same day after surgery.
Drug: tramadol/acetaminophen
Active Comparator: acetaminophen
Acetaminophen was used as active control.
Drug: acetaminophen

Primary Outcome Measures :
  1. Pain score [ Time Frame: Postoperative 48 hours ]

Secondary Outcome Measures :
  1. postoperative morphine consumption, side effect, recovery, sleeping quality, satisfaction [ Time Frame: Postoperative 48 hours ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • ASA I to III
  • Age 18 to 80 years
  • Scheduled for elective lower abdominal surgery (gynecological or colorectal surgery) at Queen Mary Hospital, Hong Kong

Exclusion Criteria:

  • Allergy to tramadol, acetaminophen, or other opioid drugs
  • Patient with epilepsy or history of seizures
  • Concurrent use of selective serotonin uptake inhibitors, tricyclic antidepressants, or monoamine oxidase inhibitors
  • Impaired or retarded mental state
  • Impaired renal function, defined as preoperative serum creatinine level over 120µmol/L
  • Impaired hepatic function, defined as preoperative serum albumin level less than 30g/L
  • Intraoperative use of clonidine or dexmedetomidine
  • Patient requiring postoperative mechanical ventilation
  • Difficulties in using patient-controlled analgesia
  • Pregnancy
  • Current or previous drug abuser
  • Alcoholism
  • Patient refusal

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00942565

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Hong Kong
Department of Anaesthesiology, The University of Hong Kong
Hong Kong, Hong Kong
Sponsors and Collaborators
The University of Hong Kong

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Responsible Party: Cheung Chi Wai, Dr., The University of Hong Kong Identifier: NCT00942565    
Other Study ID Numbers: UW 06-188 T/1213
First Posted: July 21, 2009    Key Record Dates
Last Update Posted: February 1, 2013
Last Verified: January 2013
Keywords provided by Cheung Chi Wai, The University of Hong Kong:
Open gynecological surgery
Additional relevant MeSH terms:
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Pain, Postoperative
Postoperative Complications
Pathologic Processes
Neurologic Manifestations
Signs and Symptoms
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Analgesics, Opioid
Central Nervous System Depressants