Tegaserod is a 5-HT4 receptor partial agonist that is used to effectively treat constipation-predominant irritable bowel syndrome.
It works by enhancing gastrointestinal motility and reducing visceral pain.
It is believed that through its neuromodulatory action, Tegaserod may also improve the symptoms of functional heartburn, by the same mechanisms within the esophagus.
Researchers from the Oklahoma Foundation for Digestive Research, Oklahoma City, Oklahoma, USA, therefore set out to determine if this was the case.
The scientists investigated whether Tegaserod given at 6 mg BID could do any of 3 things in patients with functional heartburn.
They compared Tegaserod to a placebo in these patients to see if the treatment could; raise esophageal pain threshold to mechanical and chemical stimuli, improve upper and lower GI symptom profile (occurrence, frequency, severity and distress), and increase global preference compared to the placebo.
Seventy patients who had given informed consent were screened, from which 42 evaluable patients with heartburn were obtained (15 male, 27 female, age range 20 – 68 years).
At screening the patients underwent esophageal manometry, 24-hour pH-metry, esophageal gastroduodenoscopy, esophageal balloon distention and Bernstein acid infusion.
| Treatment with Tegaserod was associated with a higher rate of diarrhea|
Study patients were then randomly assigned to Tegaserod 6 mg BID and placebo for 14 consecutive days, in a crossover design, separated by a 7 – 10 day washout period.
After each treatment regimen, patients underwent esophageal acid infusion and balloon distention and also completed a GI multi-symptom questionnaire, with occurrence, frequency, severity and level of distress collected for each symptom.
Following completion of the study, patients were asked to rate their preference for overall treatment regimen.
The study showed that Tegaserod significantly increased both the balloon pressure and balloon volume required to induce pain.
The mean and the maximum wall tension of the balloon at the pain threshold were also increased with Tegaserod.
Tegaserod had no effect on pain threshold to acid infusion.
However, there was a significant decrease in occurrence of heartburn/acid reflux and regurgitation, as well as a reduction in the level of distress perceived from the regurgitation, when Tegaserod was used.
Treatment with Tegaserod was associated with a higher rate of diarrhea, but despite this, no withdrawals from treatment took place as a result of this side effect.
Global treatment preference was 63.4% for tegaserod, and 12.2% for placebo. 24.4% of patients had no treatment preference.
Concluding on behalf of his fellow authors, S. Rodriguez-Stanley said, "Tegaserod significantly improved esophageal pain threshold to mechanical distention; however, tegaserod did not alter acid sensitivity."
He continued, "This supports separate chemical and mechanical pain pathways in the esophagus, " and added, "Tegaserod improved distressing upper GI symptoms in patients with functional heartburn, particularly regurgitation."