Global trends in opioid use for pain management in acute pancreatitis: A multicentre prospective observational study.

BACKGROUND: Since there is no current international consensus on the optimal approach for pain management in acute pancreatitis (AP), analgesic practices may vary across different healthcare settings. OBJECTIVE: This study explored global disparities in analgesic use, in particular opioids, during admission and at discharge in hospitalised AP patients. METHODS: This was a post hoc analysis of the prospective PAINAP database, which included all admissions for AP between April and June 2022 with a 1-month follow-up. Demographic details, analgesic use, and clinical outcomes were recorded during admission and at discharge. Odds ratios (ORs) for opioid use during admission and at discharge were identified using multivariable regression analyses. RESULTS: Amongst the 1864 patients (52% males, median age 56 (interquartile range, 41-71)) across three different continents, simple analgesics were predominantly used as the primary analgesic (70%). Opioid use during admission was lowest in European centres (67%). Admission in Asian (OR, 2.53 (95% confidence interval (CI), 1.59-4.04), p < 0.001), and Australian (OR, 5.81 (95% CI, 3.19-10.56), p < 0.001) centres was associated with opioid administration during admission compared with European centres. Increased pain severity, longer pre-admission pain duration, organ failure, and longer length of admission increased opioid use during admission. At discharge, Asian (OR, 2.01 (95% CI, 1.40-2.88), p < 0.001) and Australian (OR, 1.91 (95% CI, 1.28-2.85), p = 0.002) centres were associated with opioid prescription compared with European centres. Increased pain severity, longer pre-admission pain duration, acute necrotic collections, and walled-off necrosis also increased the likelihood of opioid prescription at discharge. CONCLUSION: There are substantial intercontinental differences in opioid use for AP pain. Accordingly, there is a need for international guidelines on pain management in AP.

Opium tincture has anti-propulsive effects in patients with chronic diarrhea: a randomized, placebo-controlled, and cross-over trial.

OBJECTIVE: Chronic diarrhea affects approximately 5% of the population. Opioids inhibit gastrointestinal motility, and opium tincture has shown anti-propulsive effects in healthy, but no controlled studies of its clinical efficacy exist. We aimed to investigate the anti-propulsive and central nervous system (CNS) effects of opium tincture in patients with chronic diarrhea. MATERIALS AND METHODS: The study was a randomized, double-blinded, placebo-controlled, cross-over trial in subjects with chronic diarrhea refractory to standard treatment. Participants received opium tincture or placebo during two intervention periods, each lasting seven days. Bowel movements were recorded daily, and gastrointestinal transit time was investigated with the wireless motility capsule system. Gastrointestinal symptoms, health-related quality of life, and CNS effects (pupil size, reaction time, memory, and general cognition) were also investigated, along with signs of addiction. RESULTS: Eleven subjects (mean age: 45 ± 17 years, 46% males) with a median of 4.7 daily bowel movements were included. The number of daily bowel movements was reduced during opium tincture treatment to 2.3 (p = 0.045), but not placebo (3.0, p = 0.09). Opium tincture prolonged the colonic transit time compared to placebo (17 h vs. 12 h, p < 0.001). In both treatment arms, there were no changes in self-reported gastrointestinal symptoms, health-related quality of life, or CNS effects, and no indication of addiction was present. CONCLUSION: Opium tincture induced anti-propulsive effects in patients with chronic diarrhea refractory to standard treatment. This indicates that opium tincture is a relevant treatment strategy for selected patients with chronic diarrhea. Moreover, no evidence of opioid-induced sedation or addiction was found.Trial Registration Number: NCT05690321 (registered 2023-01-10).

No Effect of Methylnaltrexone on Acute Pancreatitis Severity: A Multicenter Randomized Controlled Trial.

INTRODUCTION: Opioids used to manage severe pain in acute pancreatitis (AP) might exacerbate the disease through effects on gastrointestinal and immune functions. Methylnaltrexone, a peripherally acting µ-opioid receptor antagonist, may counteract these effects without changing analgesia. METHODS: This double-blind, randomized, placebo-controlled trial included adult patients with AP and systemic inflammatory response syndrome at 4 Danish centers. Patients were randomized to receive 5 days of continuous intravenous methylnaltrexone (0.15 mg/kg/d) or placebo added to the standard of care. The primary end point was the Pancreatitis Activity Scoring System score after 48 hours of treatment. Main secondary outcomes included pain scores, opioid use, disease severity, and mortality. RESULTS: In total, 105 patients (54% men) were randomized to methylnaltrexone (n = 51) or placebo (n = 54). After 48 hours, the Pancreatitis Activity Scoring System score was 134.3 points in the methylnaltrexone group and 130.5 points in the placebo group (difference 3.8, 95% confidence interval [CI] -40.1 to 47.6; P = 0.87). At 48 hours, we found no differences between the groups in pain severity (0.0, 95% CI -0.8 to 0.9; P = 0.94), pain interference (-0.3, 95% CI -1.4 to 0.8; P = 0.55), and morphine equivalent doses (6.5 mg, 95% CI -2.1 to 15.2; P = 0.14). Methylnaltrexone also did not affect the risk of severe disease (8%, 95% CI -11 to 28; P = 0.38) and mortality (6%, 95% CI -1 to 12; P = 0.11). The medication was well tolerated. DISCUSSION: Methylnaltrexone treatment did not achieve superiority over placebo for reducing the severity of AP.

Opioid analgesia and severity of acute pancreatitis: An international multicentre cohort study on pain management in acute pancreatitis.

BACKGROUND: The effect of analgesic modalities on short-term outcomes in acute pancreatitis remains unknown. However, preclinical models have raised safety concerns regarding opioid use in patients with acute pancreatitis. OBJECTIVE: This study aimed to assess the association between analgesics, particularly opioids, and severity and mortality in hospitalised patients with acute pancreatitis. METHODS: This prospective multicentre cohort study recruited consecutive patients admitted with a first episode of acute pancreatitis between April 1 and 30 June 2022, with a 1-month follow-up. Data on aetiology, clinical course, and analgesic treatment were collected. The primary outcome was the association between opioid analgesia and acute pancreatitis severity, which was analysed using univariate and multivariate analyses. RESULTS: Among a total of 1768 patients, included from 118 centres across 27 countries, 1036 (59%) had opioids administered on admission day, and 167 (9%) received opioids after admission day. On univariate analysis, moderately severe or severe acute pancreatitis was associated with male sex, Asian ethnicity, alcohol aetiology, comorbidity, predicted severe acute pancreatitis, higher pain scores, longer pain duration and opioid treatment (all p < 0.001). On multivariate analysis, comorbidity, alcohol aetiology, longer pain duration and higher pain scores increased the risk of moderately severe or severe acute pancreatitis (all p < 0.001). Furthermore, opioids administered after admission day (but not on admission day) doubled the risk of moderately severe or severe disease (OR 2.07 (95% CI, 1.29-3.33); p = 0.003). Opioid treatment for 6 days or more was an independent risk factor for moderately severe or severe acute pancreatitis (OR 3.21 (95% CI, 2.16-4.79; p < 0.001). On univariate analysis, longer opioid duration was associated with mortality. CONCLUSION: Opioid treatment increased the risk of more severe acute pancreatitis only when administered after admission day or for 6 days or more. Future randomised studies should re-evaluate whether opioids might be safe in acute pancreatitis.

Spinal Excitability in Patients with Painful Chronic Pancreatitis.

Purpose: Abdominal pain is common in patients with chronic pancreatitis (CP), but management is challenging - possibly due to altered pain processing within the central nervous system rendering conventional treatments ineffective. We hypothesized that many patients with painful CP have generalized hyperalgesia correlating with central neuronal hyperexcitability. Patients and Methods: Seventeen CP patients with pain and 20 matched healthy controls underwent experimental pain testing, including repeated pain stimuli (temporal summation), pressure algometry performed in dermatomes with same spinal innervation as the pancreatic gland (pancreatic areas) and remote dermatomes (control areas), a cold pressor test and a conditioned pain modulation paradigm. To probe central neuronal excitability, the nociceptive withdrawal reflex was elicited by electrical stimulation of the plantar skin, and electromyography was obtained from the ipsilateral anterior tibial muscle together with somatosensory evoked brain potentials. Results: Compared to healthy controls, patients with painful CP had generalized hyperalgesia as evidenced by 45% lower pressure pain detection thresholds (P<0.05) and decreased cold pressor endurance time (120 vs 180 seconds, P<0.001). In patients, reflex thresholds were lower (14 vs 23 mA, P=0.02), and electromyographic responses were increased (16.4 vs 9.7, P=0.04) during the withdrawal reflex, reflecting predominantly spinal hyperexcitability. Evoked brain potentials did not differ between groups. A positive correlation was found between reflex thresholds and cold pressor endurance time (ρ=0.71, P=0.004). Conclusion: We demonstrated somatic hyperalgesia in patients with painful CP associated with spinal hyperexcitability. This highlights that management should be directed at central mechanisms using, eg, gabapentinoids or serotonin-noradrenaline reuptake inhibitors.

Effects of opium tincture on the enteric and central nervous systems: A randomized controlled trial.

Opioids change gut motility, and opium tincture has been used for treatment of chronic diarrhoea for centuries. However, the effects have never been documented in controlled trials. We aimed to investigate the effects of opium tincture on gastrointestinal transit and motility, frequency of bowel movements, stool consistency, gastrointestinal symptoms and sedation. Twenty healthy subjects were included in this randomized controlled trial. Opium tincture or placebo was each applied for 9 days. Gastrointestinal transit and motility were investigated with the 3D-transit system. Bowel movements and gastrointestinal symptoms were recorded daily. General cognition, reaction time, memory and electroencephalography were used to assess effects on the central nervous system. Opium tincture doubled colonic transit (49 vs. 23 h, p < 0.001), decreased antegrade colonic movements (p < 0.05), reduced daily bowel movements (0.7 vs. 1.2, p < 0.001) and increased stool consistency (Type 3 vs. Type 4, p < 0.001). No changes in general cognition, reaction time or memory were observed, and minor changes of power observed by electroencephalography did not indicate sedation. This study is the first to show that opium tincture has anti-propulsive properties in the healthy gut, while no sedative effects were seen. This indicates that opium tincture is a relevant and safe treatment option in chronic diarrhoea.

Effects of the peripherally acting µ-opioid receptor antagonist methylnaltrexone on acute pancreatitis severity: study protocol for a multicentre double-blind randomised placebo-controlled interventional trial, the PAMORA-AP trial.

BACKGROUND: Moderate to severe acute pancreatitis (AP) is associated with a high rate of complications and increased mortality, yet no targeted pharmacologic treatment currently exists. As pain is a dominant symptom in AP, patients are exposed to excess levels of both endo- and exogenous opioids, which may have harmful effects on the course of AP. This trial investigates the effects of the peripherally acting µ-opioid receptor antagonist (PAMORA) methylnaltrexone on disease severity and clinical outcomes in patients with moderate to severe AP. METHODS: PAMORA-AP is a multicentre, investigator-initiated, double-blind, randomised, placebo-controlled, interventional trial, which will be conducted at four referral centres for acute pancreatitis in Denmark. Ninety patients with early-onset AP (pain onset within 48 h) as well as predicted moderate to severe disease (two or more systemic inflammatory response syndrome criteria upon admission) will be prospectively included. Subsequently, participants will be randomised (1:1) to intravenous treatment with either methylnaltrexone or matching placebo (Ringer's lactate) during 5 days of admission. The primary endpoint will be the group difference in disease severity as defined and measured by the Pancreatitis Activity Scoring System (PASS) score 48 h after randomisation. Secondary endpoints include daily PASS scores; disease severity according to the Atlanta classification; quantification of need for analgesics, nutritional support, intravenous fluid resuscitation and antibiotics; duration of hospital admissions, readmission rates and mortality. Pain intensity and gut function will be self-reported using validated questionnaires. Exploratory endpoints include circulating levels of pro-and anti-inflammatory markers, polyethylene glycol recovery from the urine, circulating levels of blood markers of intestinal permeability, the prevalence of pancreatic complications on computed tomography (CT) scans, and colon transit time assessed using a CT-based radiopaque marker method. DISCUSSION: This trial aims to evaluate the PAMORA methylnaltrexone as a novel targeted pharmacotherapy in patients with moderate to severe AP with the potential benefit of improved patient outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04743570 . Registered on 28 January 2021. EudraCT 2020-002313-18.