1. Use of opioids for moderate and severe pain

2. History of substance abuse.\*

3. Pathological conditions of the nasal cavity as contraindication to nasal fentanyl

4. Renal- or liver- failure, defined as creatinin \> 150 and alanine-amino transferase (ALAT) \> x 1.5 reference value

5. Sleep apnoea syndrome, severe chronic obstructive lung disease or illnesses leading to severe respiratory depression.

6. Psychiatric disease

7. Neurological disease giving dizziness or sedation

8. Cognitive impairment which makes the patient unable to complete questionnaires or not able to comply with the study procedures.

9. Previous or ongoing facial radiotherapy

10. Recurrent nose bleeding

11. Known hypersensitivity to the active substances or excipients of the study drugs

12. Pregnant or breastfeeding women

13. Treated with monoamine oxidase (MAO) inhibitor within the last 14 days

Nasal Fentanyl for Chronic Cancer Pain