Table 1.
Drugs acting via serotonergic mechanisms: sites of action and potential therapeutic areas.
| Class and examples | Site | Action | Potential therapeutic areas |
|---|---|---|---|
| 5HT1p agonists | Inhibitory gastric motor neurones | Fundal relaxation | Functional dyspepsia |
| Buspirone | |||
| Sumitriptam | |||
| 5HT3 antagonists | |||
| Ondansetron | Vagal afferents | Inhibit nausea due to 5HT release | Chemotherapy induced nausea |
| Granisetron | Enteric interneurones & secreto-motor neurones | Inhibit opiate induced nausea | Post operative nausea |
| Alosetron | Mesenteric afferents | Inhibit sprial evoked responses to intestinal distension | Visceral hypersensitivity in IBS |
| Cilansetron | |||
| 5HT4 antagonists | |||
| Prucalopride | Cholinergic colonic motor nerves (enhances acetylcholine release) | Stimulates peristalsis | Constipation |
| Accelerates colonic transit | |||
| 5HT4 partial agonist | |||
| Tegaserod | Primary afferent enteric neurones | Stimulates peristalsis | Constipated IBS |
| Enterocytes | Stimulates chloride secretion | ||
| Extrinsic mesenteric afferents | Inhibits afferent firing in response to distension | ||
| Combined 5HT4 agonist and 5HT3 antagonist | |||
| Cisapride | Motor neurones | Stimulates increased amplitude of oesphageal peristalsis contractions and lower oesphageal sphineter pressure | Impaired oesphageal peristalsis |
| Accelerating gastric emptying and small bowel transit | Gastroparesis | ||
| Chronic intestinal pseudo-obstruction | |||
Note that this list of known sites of action is selective and certainly incomplete since the drugs have been studied in different models and in differing detail.