The Analgesic Efficacy of Δ9-THC (Namisol®) in Patients With Persistent Postsurgical Abdominal Pain

Inclusion Criteria: * Aged 18 years or older * Pain should have developed after a surgical procedure * Pain duration exceeding 3 months, and average NRS≥3 * Stable doses intake of analgesics for the past 2 months * The patient has been informed about the study, understood the information and signed the informed consent form Exclusion Criteria: * Diagnosed irritated bowel syndrome (IBS) or chronic pancreatitis * Patient took cannabinoids on a regular basis for at least one year * Patient does not feel a pinprick test in the lower extremities * Patient has a body mass index (BMI) above 36,0 kg/m2 * Patient suffers from serious painful conditions other than chronic pancreatitis * Patient has a significant medical disorder that may interfere with the study or may pose a risk for the patient * Patient uses any kind of concomitant medication that may interfere with the study or may pose a risk for the patient * Patient does not tolerate oral intake of medication or liquids, or is refrained from oral intake because of medical reasons * Patient demonstrates clinical relevant deviations in the electrocardiogram (ECG) * Patient has an actual moderate to severe renal impairment * Patient has an actual moderate to severe hepatic impairment * Patient has a presence or history of major psychiatric illness * Patient has experienced an epileptic seizure in the past * Patient demonstrates clinically significant laboratory abnormalities * Patient demonstrates a positive urine drug screen for THC, cocaine, MDMA, and amphetamines * Patient demonstrates a positive test result on hepatitis B surface antigen, hepatitis C antibody or HIV antibody test * Patient has a history of sensitivity / idiosyncrasy to THC * Patient has a known or suspected lactose intolerance * Female patient is pregnant or breastfeeding * Patient intends to conceive a child during the course of the study * Patient participates in another investigational drug study * Patient has a clinical significant exacerbation in illness * Patient is unwilling or unable to comply with the lifestyle guidelines