Erythromycin in GI
Motilin, a 22-amino acid peptide released from endocrine cells of the upper small intestine, is the only interdigestive gut hormone. It is a potent contractile agent of the upper GI tract. Motilin causes an intracellular increase of the concentration of Ca2+, leading to a strong contractile effect. The regulation of GI motility is shown in the first section of this chapter.
The effects of motilin can be mimicked by some macrolide antibiotics such as erythromycin. This drug is used as a prokinetic agent because it can improve gastric emptying in the short term. Rapid development of tolerance to erythromycin and possible undesirable antibiotic effects limit the use of this drug as a prokinetic agent.