Erythromycin accelerates gastric emptying in gastroparesis patients by binding to motilin receptors. This binding mimics the action of motilin, a naturally occurring hormone that stimulates gastric motility.
Specifically, erythromycin activates the motilin receptor, initiating a signaling cascade. This cascade leads to increased contractions of the smooth muscles in the stomach, facilitating the movement of food through the digestive tract.
While the exact mechanisms are complex and involve multiple pathways, the key is the direct interaction with the motilin receptor. This interaction prompts smooth muscle contraction, ultimately resulting in improved gastric emptying and symptom relief for many individuals with gastroparesis.
It’s important to note this effect is most pronounced at low doses of erythromycin; higher doses may not show the same gastroprokinetic effect and can even have counterproductive consequences.
Research indicates that this mechanism is particularly helpful for patients with delayed gastric emptying caused by decreased motilin activity or receptor dysfunction.
