Nizatidine and gastric emptying in functional dyspepsia

Multidirectional Efficacy of Biologically Active Nitro Compounds Included in Medicines

The current concept in searching for new bioactive products, including mainly original active substances with potential application in pharmacy and medicine, is based on compounds with a previously determined structure, well-known properties, and biological activity profile. Nowadays, many commonly used drugs originated from natural sources. Moreover, some natural materials have become the source of leading structures for processing further chemical modifications. Many organic compounds with great therapeutic significance have the nitro group in their structure. Very often, nitro compounds are active substances in many well-known preparations belonging to different groups of medicines that are classified according to their pharmacological potencies. Moreover, the nitro group is part of the chemical structure of veterinary drugs. In this review, we describe many bioactive substances with the nitro group, divided into ten categories, including substances with exciting activity and that are currently undergoing clinical trials.

Interventions That Affect Gastrointestinal Motility in Hospitalized Adult Patients: A Systematic Review and Meta-Analysis of Double-Blind Placebo-Controlled Randomized Trials

Gastrointestinal (GI) dysmotility is a common complication in acute, critically ill, postoperative, and chronic patients that may lead to impaired nutrient delivery, poor clinical, and patient-reported outcomes. Several pharmacological and nonpharmacological interventions to treat GI dysmotility were investigated in dozens of clinical studies. However, they often yielded conflicting results, at least in part, because various (nonstandardized) definitions of GI dysmotility were used and methodological quality of studies was poor. While a universally accepted definition of GI dysmotility is yet to be developed, a systematic analysis of data derived from double-blind placebo-controlled randomized trials may provide robust data on absolute and relative effectiveness of various interventions as the study outcome (GI motility) was assessed in the least biased manner.To systematically review data from double-blind placebo-controlled randomized trials to determine and compare the effectiveness of interventions that affect GI motility.Three electronic databases (MEDLINE, SCOPUS, and EMBASE) were searched. A random effects model was used for meta-analysis. The summary estimates were reported as mean difference (MD) with the corresponding 95% confidence interval (CI).A total of 38 double-blind placebo-controlled randomized trials involving 2371 patients were eligible for inclusion in the systematic review. These studies investigated a total of 20 different interventions, of which 6 interventions were meta-analyzed. Of them, the use of dopamine receptor antagonists (MD, -8.99; 95% CI, -17.72 to -0.27; P = 0.04) and macrolides (MD, -26.04; 95% CI, -51.25 to -0.82; P = 0.04) significantly improved GI motility compared with the placebo group. The use of botulism toxin significantly impaired GI motility compared with the placebo group (MD, 5.31; 95% CI, -0.04 to 10.67; P = 0.05). Other interventions (dietary factors, probiotics, hormones) did not affect GI motility.Based on the best available data and taking into account the safety profile of each class of intervention, dopamine receptor antagonists and macrolides significantly improve GI motility and are medications of choice in treating GI dysmotility.

Radionuclide gastric emptying scintigraphy in patients with functional dyspepsia

AIM: To assess the use of gastric emptying scintigraphy with solid test meal in patients with functional dyspepsia (FD) and normal subjects.

METHODS: Forty-two patients with FD and 30 normal subjects underwent gastric emptying scintigraphy with 99mTc-DTPA labeling egg solid meal. The standard curve of gastric emptying was plotted to figure out the half-time of gastric emptying and emptying rate at 60 and 120 min by three different methods: method 1 with the radioactivity of the anterior view, method 2 with the mean value of and method 3 with the geometric mean of the radioactivity of the anterior and pastier views as the y-axis of the standard curve of gastric emptying, respectively. The differences in half-times and gastric emptying rates at 60 and 120 min figured out by the three different methods were compared between patients with FD and normal subjects.

RESULTS: One-way analysis of variance was performed to compare the differences in half-times. The half-time figured out by method 1 did not differ significantly from that by method 2 (P = 0.808, P = 0.243, P > 0.05), but the half-time figured out by method 3 differed significantly from those by methods 1 and 2 (1 vs 3: P = 0.007, P = 0.000; 2 vs 3: P = 0.035, P = 0.023; P < 0.05 for all). The half-time and gastric emptying rates at 60 and 120 min differed significantly between FD patients and normal subjects (P = 0.000). Method 1 figured out 80.9%, method 2 figured out 71.4% and method 3 figured out 90.5% of FD patients had longer half-time than normal subjects.

CONCLUSION: Radionuclide 99mTc-DTPA gastric emptying scintigraphy with solid meal is a simple, accurate, quantitative and physiologic method for measuring gastric motility in FD patients.

Prokinetics in diabetic gastroparesis

Within the last 50 years, diabetic gastroparesis has become a well recognized complication of type 1 and type 2 diabetes. It is a syndrome characterized by abnormal gastric function, resulting in delayed emptying of the stomach in the absence of any evident mechanical obstruction, predominantly manifested by early satiety, postprandial fullness, nausea, vomiting, and weight loss. The past five years have shown significant advances in its pathophysiology and in new diagnostic tests. Prokinetic medications remain the therapeutic focus for improving clinical symptoms of gastroparesis through enhanced gastric emptying. This article summarizes the present knowledge of prokinetics, with emphasis on medications currently available, as well as drugs under clinical investigation, including some agents in advanced clinical trials that are likely to be used in the treatment of diabetic gastroparesis in the future. These include the ghrelin agonists and newer 5-HT4 agonists devoid of cardiac side effects.

Does the use of nizatidine, as a pro-kinetic agent, improve gastric emptying in patients post-oesophagectomy?

PURPOSE

Delayed gastric emptying following oesophagectomy is common and can often lead to weight loss, malnutrition and a poor quality of life. Animal models have shown that nizatidine, a histamine H2-receptor antagonist, has pro-kinetic properties and can accelerate gastric emptying. Patients post-oesophagectomy require long-term acid suppression medication; if nizatidine can improve gastric emptying, it can be adopted for its dual pharmacological actions.

METHODOLOGY

Twenty consecutive patients were prospectively enrolled in this trial following oesophagectomy. All patients were more than 6 months post-surgery and had no evidence of recurrent cancer. A baseline nuclear medicine scan following a radiolabelled meal was conducted and then repeated after 1 week of nizatidine (150 mg bd) treatment. Quality of life and eating comfort data were collected.

RESULTS

Oesophagectomy causes a significant delay in gastric emptying. Early satiety (80%) and reflux (65%) were the most common post-operative complaints. The percentage of food remaining in the stomach at 60 min post-meal was significantly more than normal values in both the pre- and post-nizatidine studies. There is no advantage in using nizatidine as a pro-kinetic agent.

CONCLUSIONS

Impaired gastric emptying post-surgery causes a change in eating habits. Patients in this study did not lose a significant amount of weight despite all indicating worse eating comfort. Patients required more regular meals or snacks throughout the day and avoid foods that are difficult to swallow. It is likely that gastric motility only plays a small role in the emptying process and gravity combined with appropriate drainage procedures (pyloroplasty/pyloromyotomy) at the time of surgery are more important.

Pharmacotherapy of gastroparesis

Gastroparesis is a relatively common and often disabling condition that is characterized by a broad range of clinical presentation ranging from dyspeptic symptoms to nausea, vomiting, abdominal pain, malnutrition, frequent hospitalizations and incapacitation. The treatment of gastroparetic symptoms can be challenging to the gastroenterologist and the intensity of therapy varies with the physician's knowledge. Hence the determination that a patient is refractory to 'standard medical therapy' is an assessment that is subspeciality-based and could differ around the world depending on medications available. In this article, we review the use of available prokinetics, antiemetic agents, the approach for analgesia in the context of gastroparesis, and also discuss potential and evolving pharmacotherapies. The progress has been relatively limited as far as availability of new medications for gastroparesis is concerned; however, active research in developing newer prokinetics holds great promise for the future of management of this challenging entity.