- Planned use of drugs or agents during pretreatment phase onward that affect gastrointestinal motility and/ or prescription including laxatives including stool softeners (patients experiencing significant constipation may use a laxative as rescue medication if needed); antidiarrheals (in case of significant diarrhea loperamide may be used if needed); antacids containing magnesium or aluminum salts (only calcium containing ones are allowed); anticholinergics, antispasmodic agents (e.g., Librax, Donnatal, dicyclomine); erythromycin and other macrolides; octreotide; ondansetron or other 5-HT3 antagonists; opioids/narcotic analgesics; prokinetics (metoclopramide); serotonin re-uptake inhibitors or tricyclic antidepressants (allowed if constant doses for at least 1 month before treatment); calcium antagonists (allowed if constant doses for at least 1 month before treatment).