Low-dose intravenous erythromycin: effects on postprandial and fasting motility of the small bowel.
BACKGROUND
Erythromycin is a motilin agonist and its effects on gastrointestinal motility are dependent on both dose and whether it is administered during the postprandial or fasting state.


OBJECTIVE
To study the motility response of the small bowel to a low dose of intravenous erythromycin after meal intake and during fasting.


METHODS
Eighteen healthy subjects with mean age of 25 years were studied by small bowel manometry. Erythromycin was administered intravenously (0.75 mg per kg body weight) during 20 min in the postprandial (n=9) and the fasting state (n=9), and the motility response was recorded.


RESULTS
Erythromycin significantly reduced the frequency of propagated contractions (P < 0.001) and the amplitude of contractions (P < 0.02) in the small bowel during established postprandial motility. During the fasting state, erythromycin invariably initiated a phase III-like activity, which was similar to the spontaneous nocturnal phase III and migrated significantly more slowly than the diurnal phase III (P < 0.01).


CONCLUSIONS
A low dose of erythromycin administered intravenously during the postprandial state significantly inhibits small bowel motility, whereas administration during the fasting state initiates a phase III resembling the nocturnal rather than the diurnal phase III. These effects of erythromycin may indicate interference with vagal pathways. Due to its inhibitory effects, the clinical use of erythromycin in patients with hypomotility should be reconsidered, and the potential usefulness of these effects in patients with exaggerated intestinal motility deserves further attention.
Medhus
A W
AW
Department of Medicine, Ullevâl University Hospital, Oslo, Norway. asle.medhus@ioks.uio.no
Bondi
J
J
Gaustad
P
P
Husebye
E
E
D000328:Adult; D004917:Erythromycin / Q000008:administration & dosage* / Q000494:pharmacology; D005215:Fasting / Q000502:physiology*; D005260:Female; D018565:Food-Drug Interactions / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D007262:Infusions, Intravenous; D007421:Intestine, Small / Q000187:drug effects*; D008297:Male; D008365:Manometry; D013997:Time Factors
D004917:Erythromycin