Novel therapeutic agents in neurogastroenterology: advances in the past year

Sacral neuromodulation in children and adolescents with defecation disorders

BACKGROUND

Even if understanding of neuronal enteropathies, such as Hirschsprung's disease and functional constipation, has been improved, specialized therapies are still missing. Sacral neuromodulation (SNM) has been established in the treatment of defecation disorders in adults. The aim of the study was to investigate effects of SNM in children and adolescents with refractory symptoms of chronic constipation.

METHODS

A two-centered, prospective trial has been conducted between 2019 and 2022. SNM was applied continuously at individually set stimulation intensity. Evaluation of clinical outcomes was conducted at 3, 6, and 12 months after surgery based on the developed questionnaires and quality of life analysis (KINDLR). Primary outcome was assessed based on predefined variables of fecal incontinence and defecation frequency.

KEY RESULTS

Fifteen patients enrolled in the study and underwent SNM (median age 8.0 years (range 4-17 years)): eight patients were diagnosed with Hirschsprung's disease (53%). Improvement of defecation frequency was seen in 8/15 participants (53%) and an improvement of fecal incontinence in 9/12 patients (75%). We observed stable outcome after 1 year of treatment. Surgical revision was necessary in one patient after electrode breakage. Urinary incontinence was observed as singular side effect of treatment in two patients (13%), which was manageable with the reduction of stimulation intensity.

CONCLUSIONS

SNM shows promising clinical results in children and adolescents presenting with chronic constipation refractory to conservative therapy. Indications for patients with enteral neuropathies deserve further confirmation.

DA-9701 improves colonic transit time and symptoms in patients with functional constipation: A prospective study

BACKGROUND AND AIM

DA-9701, a newly developed prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, has been shown to effectively treat functional dyspepsia. Recently, it has also been suspected to improve gastrointestinal motor function. The aims of this study were to assess the effect of DA-9701 on colonic transit time (CTT) and symptoms of functional constipation.

METHODS

Thirty-three patients with functional constipation based on the Rome III criteria were prospectively enrolled. The patients received 30-mg DA-9701 three times a day for 24 days. CTT was estimated initially and at the end of treatment. Symptoms such as spontaneous bowel movements, straining, stool form, feeling of incomplete emptying and anorectal blockage, abdominal discomfort and pain, overall defecation satisfaction, and incidence of adverse events were also analyzed.

RESULTS

Twenty-seven patients completed the study. DA-9701 was associated with a significantly reduced CTT from 34.9 ± 17.6 to 23.7 ± 19.1 h (P = 0.001). Segmental CTT also significantly decreased after treatment (right CTT: from 16.8 [0.0-28.8] to 6.0 [0.0-25.2] hours, P < 0.001; rectosigmoid transit time: from 13.2 [0.0-38.4] to 6.0 [0.0-33.6] hours, P = 0.021). In addition, all constipation-related subjective symptoms, including spontaneous bowel movement frequency, significantly improved compared with those before treatment. Serious adverse events did not occur.

CONCLUSIONS

DA-9701 accelerates colonic transit and safely improves symptoms in patients with functional constipation. Therefore, we suggest that this novel agent could help to treat patients with this condition.

Pediatric enteric neuropathies: diagnosis and current management

PURPOSE OF REVIEW

Neurointestinal diseases are increasingly recognized as causes of significant gastrointestinal morbidity in children. This review highlights the most common pediatric enteric neuropathies and their diagnosis and management, emphasizing insights and discoveries from the most recent literature available.

RECENT FINDINGS

The embryologic and histopathologic causes of enteric neuropathies are varied. They range from congenital aganglionosis in Hirschsprung disease, to autoimmune-mediated loss of neuronal subtypes in esophageal achalasia and Chagas disease, to degenerative neuropathies in some cases of chronic intestinal pseudo-obstruction and gastroparesis. Increased awareness of the clinical presentation and diagnostic evaluation of these conditions is essential as it allows for earlier initiation of treatment and improved outcomes. Most current therapies, which include medical management, neurostimulation, and operative intervention, aim to minimize the symptoms caused by these conditions. The evidence base for many of these treatments in children is poor, and multiinstitutional prospective studies are needed. An innovative therapy on the horizon involves using neuronal stem cell transplantation to treat the underlying disorder by replacing the missing or damaged neurons in these diseases.

SUMMARY

Although recent advances in basic and clinical neurogastroenterology have significantly improved our awareness and understanding of enteric neuropathies, the efficacy of current treatment approaches is limited. The development of novel therapies, including pharmacologic modulators of neurointestinal function, neurostimulation to enhance gut motility, and neuronal cell-based therapies, is essential to improve the long-term outcomes in children with these disorders.

Prokinetic effects of a new 5-HT4 agonist, YKP10811, on gastric motility in dogs

BACKGROUND AND AIM

Prokinetics have been considered the first-line medicine for treating delayed gastric emptying. The aim of this study was to explore the effects and mechanisms of a new 5-HT₄ receptor agonist, YKP10811, on gastric motility in dogs.

METHODS

Four experiments were performed in dogs: (i) dose-response effects of YKP10811 on liquid gastric emptying; (ii) effects and mechanisms of YKP10811 on solid gastric emptying delayed by glucagon; (iii) effects of low-dose YKP10811 on antral contractions; and (iv) effects of low-dose YKP10811 on gastric accommodation.

RESULTS

No adverse events or cardiac dysrhythmia was noted. (i) High-dose YKP10811 (30 mg/kg) accelerated liquid gastric emptying from 15 to 90 min without inducing adverse events or cardiac dysrhythmia. YKP10811 at low doses (0.3, 1, and 3 mg/kg) accelerated gastric emptying in a dose-dependent manner. (ii) YKP10811 (0.1 mg/kg), but not tegaserod (0.3 mg/kg), significantly accelerated glucagon-induced delayed gastric emptying of solid, and the effect was completely blocked by GR113808. (iii) YKP10811 (0.3 mg/kg) enhanced antral contractions. (iv) YKP10811 did not alter gastric accommodation.

CONCLUSIONS

YKP10811 seems to improve antral contractions and accelerate gastric emptying without altering gastric accommodation in dogs via the 5-HT₄ mechanism and is substantially more potent than tegaserod. No adverse events were noted at a dose 300 times the lowest effective dose. YKP10811 may have a therapeutic potential for gastroparesis.

Psychological mislabeling of chronic pain: lessons from migraine in the 20th century

Starting with Freud, psychoanalytically oriented practitioners described a complex of unconscious conflicts, desires and personality traits they believed to be the primary cause of a wide range of medical disorders. This was the psychogenic model. With the advance of basic research and pharmacotherapy, the psychogenic model was gradually replaced by a biopsychobehavioral model. This model treats chronic pain as a biologically based disorder that can be influenced by psychological factors and lifestyle. The present paper argues that many patients with chronic pain may not be significantly impacted by psychological factors, and that for those who are, cognitive-behavioral therapy is the treatment of choice.

Clinical aspects of neurointestinal disease: Pathophysiology, diagnosis, and treatment

The enteric nervous system (ENS) is involved in the regulation of virtually all gut functions. Conditions referred to as enteric neuropathies are the result of various mechanisms including abnormal development, degeneration or loss of enteric neurons that affect the structure and functional integrity of the ENS. In the past decade, clinical and molecular research has led to important conceptual advances in our knowledge of the pathogenetic mechanisms of these disorders. In this review we consider ENS disorders from a clinical perspective and highlight the advancing knowledge regarding their pathophysiology. We also review current therapies for these diseases and present potential novel reparative approaches for their treatment.

Long-term outcomes of gastric electrical stimulation in children with gastroparesis

BACKGROUND

Gastric electrical stimulation (GES) has been used in adults with gastroparesis. However its use has been limited in children. We describe the largest experience with GES in children with long-term outcomes.

METHODS

Data were collected on children who underwent GES over a 10-year period. Data regarding demographics, medical history, hospital course, and outcomes were collected and analyzed. Symptom scores (validated Likert scores) were compared using a paired Student's t test.

RESULTS

Overall, 97 patients underwent GES, and a majority were teenage Caucasian girls. Ninety-six had temporary GES (tGES), and 66 had improvement in their symptoms. A total of 67 underwent permanent implantation (pGES), and there was significant reduction in all individual symptoms (p<0.001) as well as the total symptom score (TSS) (p<0.0001) at 1, 6, 12, and >12 months. Recurrence of symptoms leading to device removal occurred in 7 cases. Forty-one patients had continued improvement in symptoms for over 12 months, with a mean follow-up of 3.5 years (range 1-9 years).

CONCLUSIONS

This study represents the largest experience of systematic application of GES in children. GES is a safe and effective therapy for selected children with intractable GP with continued symptomatic improvement at 1 year and beyond.

Drug-drug interactions in pharmacologic management of gastroparesis

BACKGROUND

Gastroparesis is a disorder characterized by delayed gastric emptying due to chronic abnormal gastric motility. The treatment of the disease often entails the co-administration of several classes of pharmacological agents. These agents may be metabolized via the same pathway. Inhibition or induction of a shared metabolic pathway leads to change in the systemic levels of prescribed drugs, possibly leading to undesired clinical outcomes.

PURPOSE

This review discusses different pharmacological treatment for gastroparesis patients and describes the potential for drug-drug interactions (DDIs) in some of the combinations that are currently used. Prokinetic agents such as metoclopramide and domperidone are the cornerstone in treatment of gastroparesis. Antiemetic agents such as promethazine and ondansetron are frequently administered to gastroparesis patients to reduce nausea and vomiting. Gastroparesis is prevalent in diabetic patients and therefore antidiabetic agents are also prescribed. Many of these co-administered drugs are metabolized via common drug metabolizing enzymes and this can trigger potential DDIs. The scientific literature was reviewed from the years 1975-2014 for original research articles and reviews that evaluated DDIs in gastroparesis. Many commonly prescribed combinations were predicted to cause potential DDIs in gastroparesis patients. This review will help inform about potential hazardous combinations. This information will hopefully lead to less adverse effects and more successful gastroparesis management.

Gastroparesis in children

PURPOSE OF REVIEW

Gastroparesis is a disorder with delayed gastric emptying in the absence of mechanical obstruction. It is one of the more common dysmotilities that occur in the gastrointestinal tract, and is thought to primarily affect adults. Pediatric cases of gastroparesis were considered rare; however, recent evidence suggests growing recognition in children and adolescents. Therefore, it is important for the pediatric caregiver to understand the condition and the treatment options available.

RECENT FINDINGS

The majority of patients are women, and presentation is usually with symptoms of persistent nausea, emesis, postprandial pain and bloating, and early satiety. Weight loss may occur in some cases, though this is not universal. The majority of cases are idiopathic, with diabetes mellitus the second most common cause.

SUMMARY

Treatment consists of symptomatic relief with medication to counteract the nausea, emesis, pain, bloating, gastroesophageal reflux, early satiety, and improve gastric emptying. Dietary modification is also used with small meals and avoidance of high fiber and fat-containing foods. Recalcitrant cases of gastroparesis require the use of additional approaches such as jejunal feeds, intrapyloric botulinum toxin, gastric emptying procedures such as pyloroplasty, and gastric electrical stimulation. We will review these options in this article.

Progress in the treatment of small fiber peripheral neuropathy

Small fiber neuropathy is a syndrome of diverse disease etiology because of multiple pathophysiologic mechanisms with major presentations of neuropathic pain and autonomic symptoms. Over the past decade, there has been substantial progress in the treatments for neuropathic pain, dysautonomia and disease-modifying strategy. In particular, anticonvulsants and antidepressants alleviate neuropathic pain based on randomized clinical trials.

Mindfulness-based therapies in the treatment of functional gastrointestinal disorders: a meta-analysis

Background. Functional gastrointestinal disorders are highly prevalent and standard treatments are often unsatisfactory. Mindfulness-based therapy has shown benefit in conditions including chronic pain, mood, and somatization disorders. Objectives. To assess the quality and effectiveness reported in existing literature, we conducted a meta-analysis of mindfulness-based therapy in functional gastrointestinal disorders. Methods. Pubmed, EBSCO, and Cochrane databases were searched from inception to May 2014. Study inclusion criteria included randomized, controlled studies of adults using mindfulness-based therapy in the treatment of functional gastrointestinal disorders. Study quality was evaluated using the Cochrane risk of bias. Effect sizes were calculated and pooled to achieve a summary effect for the intervention on symptom severity and quality of life. Results. Of 119 records, eight articles, describing seven studies, met inclusion criteria. In six studies, significant improvements were achieved or maintained at the end of intervention or follow-up time points. The studies had an unclear or high risk of bias. Pooled effects were statistically significant for IBS severity (0.59, 95% CI 0.33 to 0.86) and quality of life (0.56, 95% CI 0.47 to 0.79). Conclusion. Studies suggest that mindfulness based interventions may provide benefit in functional gastrointestinal disorders; however, substantial improvements in methodological quality and reporting are needed.