Prokinetic activity of nizatidine: implications for the management of patients with gastroesophageal reflux disease

Effect of acotiamide on gastric emptying in healthy adult humans

BACKGROUND

Acotiamide is a first-in-class drug that is used to treat functional dyspepsia (FD). It is considered that acotiamide acts as an antagonist on muscarinic autoreceptors in the enteric nervous system and inhibits acetylcholinesterase activity. We examined the effect of acotiamide on gastric emptying in healthy adult humans.

MATERIALS AND METHODS

Twelve healthy adult males were enrolled in this double-blind crossover study. Acotiamide or placebo was administered orally in the 12 subjects 30 min before ingestion of a nutritional liquid meal (400 Kcal/400 mL). Six of the 12 participants took 100 mg of acotiamide or placebo, and six of the 12 participants took 300 mg of acotiamide or placebo in a double-blind crossover fashion. All subjects underwent measurement of gastric emptying by the (13) C breath test.

RESULTS

After the meal with placebo was ingested, the %dose/h curve ascended. The %dose/h curve after a meal with 100 or 300 mg of acotiamide ascended in an identical manner compared with the results with placebo. No significant differences were observed at any studied time point, and there were no significant changes in gastric emptying parameters (gastric emptying coefficient, t-1/2ex and t-lag ex).

CONCLUSIONS

A single administration of 100 or 300 mg of acotiamide did not affect gastric emptying after a liquid meal in healthy adult humans. Acotiamide has profound effects on restoring delayed gastric emptying and impaired accommodation in patients with FD but may have no effect on gastric emptying in healthy subjects. Such pharmacological actions have not been observed in previous gastroprokinetic studies.

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.

Influence of acid suppressants on gastric emptying: cross-over analysis in healthy volunteers

BACKGROUND

Gastric emptying plays an important role in gastroesophageal reflux disease. Acid suppressants such as H2 receptor antagonists and/or proton pump inhibitors are often used in patients with gastroesophageal reflux disease. However, it remains controversial whether H2 receptor antagonists and proton pump inhibitors delay or accelerate gastric emptying. Here, the influence of acid suppressants on gastric emptying was evaluated via a cross-over study using the [13C]-labeled acetate breath test.

METHODS

Twenty normal male subjects without gastroesophageal reflux disease symptoms were enrolled. Gastric emptying was investigated five times in every subject by the [13C]-labeled acetate breath test with oral administration of the vehicle, domperidone, and three acid suppressants: ranitidine, famotidine and rabeprazole. Gastric emptying was estimated by the values of T(max-calc), T(1/2) and %dose/2 h calculated from the 13CO2 breath excretion curve.

RESULTS

Using the T(max-calc) values, rabeprazole, ranitidine and famotidine did not influence gastric emptying time in comparison with vehicle administration. Using the T(1/2) and %dose/2 h values, rabeprazole tended to delay gastric emptying. Domperidone produced a statistically significant acceleration of gastric emptying for all three variables (P < 0.05).

CONCLUSION

Oral dosage of the H2 receptor antagonists, ranitidine and famotidine, has no significant effect on gastric emptying. However, rabeprazole may delay gastric emptying more strongly than H2 receptor antagonists.