Effects of thienorphine on contraction of the guinea pig sphincter of Oddi, choledochus and gall bladder

Lower prevalence of gastroesophageal reflux disease in patients with noncardiac chest pain on opiates: a cross-sectional study

Opiates can cause heartburn and spastic esophageal dysmotility but their role in noncardiac chest pain (NCCP) is not known. Our aim was to characterize opiate effects on esophageal function using esophageal pH monitoring and high-resolution manometry (HREM) in these patients.We performed a cross sectional study of opiate users with NCCP who underwent HREM and esophageal pH study from 2010 to 2017 using opiate nonusers as a comparison group. Demographic data, symptoms, opiate use, endoscopic findings, esophageal pH study parameters, and HREM data were abstracted.Thirty three patients with NCCP on opiates were compared to 144 opiate non-users. Compared to opiate nonusers, opiate users had lower total acid exposure (2.3% vs. 3%, P = 0.012), lower upright acid exposure (1.2% vs. 3.1%, P = 0.032) and lower DeMeester score (6.5 vs. 12.7, P = 0.016). Opiate users also had higher lower esophageal sphincter integrated relaxation pressure (LES-IRP) (7.0 mm Hg [2.2, 11.7] vs. 3.7 mm Hg [1.1, 6.2] P = 0.011) and greater mean distal contractile integral (DCI) (2575 mm.Hg.s.cm [1134, 4466] vs. 1409 mm.Hg.s.cm [796, 3003] P = 0.03) than opiate non-users. The prevalence of hypertensive motility disorders (15.2% vs. 11.1%) and achalasia (12.1% vs. 2.1%) was higher in opiate users (P = 0.039) but did not reach significance on multivariate analysis.In patients presenting with NCCP, opiate users had lower esophageal acid exposure compared to opiate nonusers. This might be due to higher LES pressures preventing reflux and higher DCI leading to more rapid acid esophageal clearance.

Opioid misuse in gastroenterology and non-opioid management of abdominal pain

Opioids were one of the earliest classes of medications used for pain across a variety of conditions, but morbidity and mortality have been increasingly associated with their chronic use. Despite these negative consequences, chronic opioid use is increasing worldwide, with the USA and Canada having the highest rates. Chronic opioid use for noncancer pain can have particularly negative effects in the gastrointestinal and central nervous systems, including opioid-induced constipation, narcotic bowel syndrome, worsening psychopathology and addiction. This Review summarizes the evidence of opioid misuse in gastroenterology, including the lack of evidence of a benefit from these drugs, as well as the risk of harm and negative consequences of opioid use relative to the brain-gut axis. Guidelines for opioid management and alternative pharmacological and nonpharmacological strategies for pain management in patients with gastrointestinal disorders are also discussed. As chronic pain is complex and involves emotional and social factors, a multimodal approach targeting both pain intensity and quality of life is best.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.