Study protocol for a randomised, double-blinded, placebo-controlled, clinical trial of S-ketamine for pain treatment in patients with chronic pancreatitis (RESET trial).

INTRODUCTION: Chronic pancreatitis (CP) is an inflammatory disease that causes irreversible damage to pancreatic tissue. Pain is its most prominent symptom. In the absence of pathology suitable for endoscopic or surgical interventions, pain treatment usually includes opioids. However, opioids often have limited efficacy. Moreover, side effects are common and bothersome. Hence, novel approaches to control pain associated with CP are highly desirable. Sensitisation of the central nervous system is reported to play a key role in pain generation and chronification. Fundamental to the process of central sensitisation is abnormal activation of the N-methyl-D-aspartate receptor, which can be antagonised by S-ketamine. The RESET trial is investigating the analgaesic and antihyperalgesic effect of S-ketamine in patients with CP.

METHODS AND ANALYSIS: 40 patients with CP will be enrolled. Patients are randomised to receive 8 h of intravenous S-ketamine followed by oral S-ketamine, or matching placebo, for 4 weeks. To improve blinding, 1 mg of midazolam will be added to active and placebo treatment. The primary end point is clinical pain relief as assessed by a daily pain diary. Secondary end points include changes in patient-reported outcome measures, opioid consumption and rates of side effects. The end points are registered through the 4-week medication period and for an additional follow-up period of 8 weeks to investigate long-term effects. In addition, experimental pain measures also serves as secondary end points, and neurophysiological imaging parameters are collected. Furthermore, experimental baseline recordings are compared to recordings from a group of healthy controls to evaluate general aspects of pain processing in CP.

ETHICS AND DISSEMINATION: The protocol is approved by the North Denmark Region Committee on Health Research Ethics (N-20130040) and the Danish Health and Medicines Authorities (EudraCT number: 2013-003357-17). The results will be disseminated in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER: The study is registered at https://www.clinicaltrialsregister.eu (EudraCT number 2013-003357-17).