​Mechanism of Action

Naronapride is an orally bioavailable, small organic molecule. It was designed to be a potent and selective serotonin 5-HT4 receptor agonist and D2 antagonist. Stimulating 5-HT4 receptors in the gut wall promotes the release of acetylcholine, which works to increase motility of the GI tract. Inhibiting D2 receptors removes the “brakes” on motility of the gut. The high 5-HT4 receptor selectivity minimizes the potential for off-target pharmacological effects. Naronapride’s local action in the gut wall with minimal concentrations in the blood stream further reduces the risk of unwanted effects. Indeed, naronapride has been shown in animal and in human studies to be safe and devoid of adverse cardiovascular effects. Combined 5-HT4 receptor stimulation with D2 receptor inhibition has been proven to be the most effective treatment for motility disorders.