Inclusion Criteria:

- Male or female outpatients aged from 18 to 70 years with cancer chronic pain who
received in the last 4 weeks at least 40 mg of oral morphine or equianalgesic dose of
other opioids. If using adjuvant analgesics, these must be in stable doses in the
last 4 weeks.

Exclusion Criteria:

- Life expectancy bellow 4 months;

- Karnofsky score < 60;

- Hypersensitivity to opioids or patches;

- Acute pain;

- Non cancer pain;

- Increased intracranial pressure;

- Conditions that prevent the patient to understand the study directions and/or give
his consent;

- Neuromuscular disorders with increased risk of respiratory depression;

- Impossibility to receive rescue oral morphine; active infections;

- Fever;

- Pregnancy and nursing;

- Uncontrolled diabetes mellitus or arterial hypertension;

- Need of anticoagulation;

- Need to operate machines or vehicles;

- Important skin disorders;

- History of severe allergic reactions;

- BMI ≥ 35;

- Safety exams outrange;

- Participation in another clinical trial within the last 2 months;

- Investigator´s opinion.