Patient description: The patient is a 57-year-old man with abdominal pain and vomiting. The pain started gradually about 20 hours ago in the epigastric and periumbilical regions, radiating to his back. He drinks around 60 units of alcohol per week and smokes 22 cigarettes per day. He is healthy with no history of allergies or using any medications. His family history is positive for type 2 diabetes (his father and sister). He lives alone and has no children. The abdomen is tender and soft. His bowel sounds are normal. His heart rate is 115/min and blood pressure 110/75 mmHg. The lab results are remarkable for leukocytosis (19.5), urea of 8.5, high CRP (145), high amylase (1200) and Glc level of 15. Cross-sectional imaging was negative for obstructive pancreatitis.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Painful Chronic Pancreatitis Visceral Pain Neuropathic Pain Patients from the ages of 18 with a diagnosis of CP diagnosed using the Mayo Clinic diagnostic criteria The participants must be able to read and understand Danish The patients must suffer from chronic abdominal pain characteristic for CP, meet the for chronic pain (pain ≥ 3 days per week in at least 3 months) and must consider their pain as insufficiently treated with their usual analgesic treatment Personally, signed and dated informed consent document indicating that the patient has been informed of all pertinent aspects of the trial as well as signing the following document: "Informeret samtykke om opbevaring af biologisk material i biobank til fremtidig forskning" Personally, signed and dated the Power of attorney document (Fuldmagtserklæring) indicating that the patient has accepted that the Danish Medical Agency Sundhedsstyrelsen/Lægemiddelstyrelen) have access to the medical records Patients willing and able to comply with the scheduled visits, treatment plan, laboratory tests and other trial procedures  Patients with any clinically significant abnormalities that in the opinion of the investigator may increase the risk associated with trial participation or may interfere with the interpretation of the trial results Alcohol dependence (Alcohol use in accordance with the recommendations by the Danish Health and Medicines Authority are allowed) Illegal drug dependencies Participating in another study where investigational drug is used Patients must not suffer from painful conditions other than CP that make them unable to distinguish the pain associated with CP from chronic pain of other origin Cardiovascular diseases Low blood pressure < 100/60 Not able to understand or follow the instructions Any condition with elevated intracranial pressure Female patients who are pregnant or lactating, or intend to become pregnant and male patients who intend to father a child during the course of the study. A pregnancy test will be conducted at baseline and after 8 weeks to ensure that female patients are not pregnant during the study medication period. The investigator will have to urge that fertile female patients use a safe contraception method during the study and for at least 15 hours after termination of the study medication period. The following methods are considered as safe contraception methods