Effects of macrolide antibiotics on gastrointestinal motility in fasting and digestive states.

The effect of macrolide antibiotics on gastrointestinal motility was studied in unanaesthetized dogs by using strain-gauge transducers. Midecamycin acetate, leucomycin, josamycin and acetylspiramycin, which are 16-membered macrolides, did not affect the gastrointestinal motility and no symptoms of gastrointestinal disorder were observed. On the other hand, erythromycin, roxithromycin, clarithromycin and oleandomycin, which are 14-membered macrolides, caused giant contraction and disorder symptoms. Moreover, it was found that the glycosidic linkages of the lactone ring were necessary for a structure to exert strong contractile activity.