Inclusion Criteria:

- The patient has stable strong opioid use equipotent to 30-240 mg oral morphine
sulphate daily for a minimum of 2 weeks prior to entering the run-in phase.

- The patient has opioid-sensitive pain caused by active cancer.

- The patient is aged minimum 18 years.

Exclusion Criteria:

- The patient has a life expectancy less than 2 months.

- The patient has received chemotherapy or radiation therapy less than 4 weeks prior
to entering run-in phase

- Patients with medical conditions contraindicating morphine treatment

- The patient has hepatic disease or impaired kidney function

- The patient is taking monoamine oxidase inhibitors (MAOIs) or has taken a MAOI within
two weeks prior to entering baseline.

- The patient is taking other opioid agonists or antagonists, zidovudine or cimetidine.