Using Magnetic Resonance (MR) to Understand the Effect of Erythromycin on Bowel Motility

Magnetic Resonance (MR) Evaluation of the Effect of Erythromycin Upon Gastric and Small Bowel Motility

Magnetic Resonance Imaging (MRI) has proven to be a valuable imaging technique for suspected small bowel disease. This technique depends, in part, on adequate distension of the small bowel. This is accomplished by administering large volumes of a non-absorbable oral contrast material prior to the examination, which typically produces excellent distension of the distal small bowel and stomach, but poor distension of the proximal small bowel. Erythromycin is a common antibiotic that is known to promote stomach emptying and is used to treat diabetics with gastroparesis (poor stomach emptying.) The hypothesis of this study was that erythromycin will increase gastric emptying and hence improve small and large intestinal distention during MRI.

Gastric, small, and large intestinal volumes were assessed with MRI after ingestion of a low concentration of barium sulfate solution (1350 mL) and randomization to erythromycin 200 mg i.v.) or placebo in 40 healthy volunteers. Magnetic Resonance Images of the abdomen were acquired with a torso phased array coil and a 1.5 tesla magnet.

Inclusion Criteria:

• Normal healthy adult volunteers without known gastrointestinal disease
• Aged 18-70 years
• Able to provide written informed consent before participating in the study
• Able to communicate adequately with the investigator and to comply with the requirements for the entire study.

Exclusion Criteria:

• Known allergy to erythromycin;
• Use of drugs that have known contraindication with erythromycin (concomitant therapy with astemizole, cisapride, pimozide, or terfenadine)
• Corrected QT interval on EKG >460 msec
• Certain medications (i.e., theophylline, digoxin, oral anti-coagulant, benzodiazepine, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors) will either be excluded from the study or, if medically safe, will be asked to discontinue the medication for 4 half-lives before beginning the study.
• Use of medications that alter GI motility e.g., narcotics, medications with significant anticholinergic effects
• Pregnant or breast-feeding females
• Known claustrophobia
• Known family history of sudden death or congenital QT prolongation
• Presence of pacemaker, internal defibrillator, or other non-MR compatible device
• Patients with known metal present within their abdomen