insufficient enrollment

34 adult (>18 years) cancer pain outpatients with Opioid base therapy because of pain and breakthrough pain or extreme pain on movement will be included in this prospective, randomized, double-blind crossover study.

Over a period of 3 weeks patients will go through 3 treatment arms, each one lasting one week: Group A receives morphine drops and Placebo spray, Group B receives ketamine/chitosan spray nasal and Placebo drops and Group C receives morphine drops and ketamine/chitosan spray nasal.

Primary endpoint is time to onset of action of intranasal ketamine compared with morphine drops. Secondary endpoint is the median numeric rating scale (NRS) improvement after using the spray or morphine or the combination of ketamine spray and morphine drops.

Inclusion Criteria:

• Cancer pain in outpatients with:
• Opioid based therapy due to pain
• Breakthrough pain or
• Extreme pain on movement
• Age >= 18 years

Exclusion Criteria:

• Patients unable to give written informed consent
• Patients unable to understand how to handle and document the use of the study medication
• Known drug allergies or intolerance to ketamine
• Known drug allergies or intolerance to morphine
• Known allergy to crustacea or chitosan
• Patients using snuff at a regular basis
• Recreational drug addiction or abuse
• Serious intranasal or epipharyngeal Problems (Septum wall defects, cancer)
• Mental/psychiatric disorder
• Patients with renal failure (clearance < 30 ml/min)
• Pregnancy and breast feeding mothers
• Patients not understanding German
• Patient having arterial hypertonia with measured values > 180/95