An Efficacy and Safety Study to Compare Morphine 6-glucuronide (M6G) and Morphine in Patients Suffering With Post-Operative Pain for at Least 24 Hours

Inclusion Criteria:

• Male or female patients undergoing any of the following elective surgical proceduresthat, in the Investigator's opinion, would have required the use of post-operativepatient controlled analgesia for a minimum of 24 hours:
• Abdominal hysterectomy with the exception of laparoscopic procedures.
• Bowel / gastrointestinal (GI) surgery
• Major urological surgery
• Aged ≥ 18 years
• American Society of Anesthesiologists (ASA) grades I to III
• If female, the patient had to be post-menopausal (last menstruation > 1 yearpreviously), or surgically sterile (e.g. full hysterectomy or tubal ligation). Ifneither of these was the case, she had to use adequate contraception (i.e. hormonalcontraceptive, intrauterine device (IUD), or a double barrier method) and to have anegative urine pregnancy test during the 24-hours prior to surgery.
• Provide written informed consent to participate in the trial prior to surgery.

Exclusion Criteria:

• The patient was pregnant or lactating.
• Had a known sensitivity to morphine or other opiates, or a medical condition such thatopiates were contraindicated.
• Had a known sensitivity to paracetamol, or a medical condition such that paracetamolwas contraindicated.
• Had received any investigational drug within the 90 days prior to the start of thestudy, or was scheduled to receive one during the study period.
• Had been involved in any previous M6G study.
• Had a documented history or current evidence of alcohol or drug abuse within the yearprior to screening.
• Had clinically significant findings on pre-treatment evaluations (e.g. laboratoryresults, electrocardiograms, medical history, physical examination) that, in theInvestigator's opinion, should have excluded them from the study.
• Had a concurrent disorder that resulted in excessive pain that, in the Investigator'sopinion, would have interfered with the pain assessments during the study (e.g.severerheumatoid arthritis, muscle dystrophy or neuropathic pain).
• Had a blood clotting disorder or other blood dyscrasias.
• Had requested the use of epidural or intrathecal anaesthesia techniques.
• Required the use of a local anaesthetic block and/or infiltration of wound sites.
• Required the concomitant use of opioids or non-steroidal anti-inflammatorydrugs(NSAIDs) during the study due to an existing concurrent condition.
• Had a history of Left Ventricular Failure or compromised cardiovascular function,defined as New York Heart Association (NYHA) level 3.
• Had a history of severe renal impairment or a creatinine level > 3 times the upperlimit of normal.
• Was having surgery that would have prevented the use of oral or rectal paracetamol(ivadministration of paracetamol was not allowed).
• Was expected to require prolonged ventilation after surgery.
• Was opioid tolerant or had a history of chronic opioid use.
• Had cognitive impairment that would, in the Investigator's opinion, have precludedparticipation or compliance with protocol defined procedures (i.e. use of PCA).