title: Prokinetic effects of mirtazapine on gastrointestinal transit.
abstract: Mirtazapine is a noradrenergic and specific serotonergic antidepressant. The aim of this study was to investigate the effects of mirtazapine on gastrointestinal motility in dogs, including solid gastric emptying, antral and small intestinal contractions, and small intestinal and colonic transit. Six dogs were implanted with two cannulas located at the duodenum and the ascending colon; another six dogs were implanted with gastric cannula 6 cm proximal to the pylorus. Mirtazapine 45 mg was administered orally 90 min before the study. We found that 1) Mirtazapine accelerated gastric emptying during the entire 3 h in normal dogs (P < 0.04) and accelerated delayed gastric emptying induced by rectal distention (P < 0.04). 2) Mirtazapine restored impaired gastric tone and accommodation induced by rectal distention (P < 0.05). 3) No significant changes were noted in small intestinal contractions or transit with mirtazapine (P > 0.1). 4) Mirtazapine accelerated colonic transit at 2 and 4 h but not 6 h. The geometric center was increased from 1.9 ± 0.6 to 3.0 ± 0.5 and 3.9 ± 0.5 to 4.7 ± 0.1 at 2 and 4 h respectively (P = 0.04 vs. corresponding control). In conclusion, mirtazapine improves gastric emptying in healthy dogs and normalizes rectal distention-induced delay in gastric emptying and accelerates colon but not small intestinal transit in healthy dogs. Clinical studies are warranted to assess the effects of mirtazapine on gastrointestinal motility and sensory functions in patients with functional gastrointestinal diseases.
authors.affiliation: Division of Gastroenterology, University of Texas Medical Branch, Galveston, Texas;
authors.forename: Jieyun
authors.initials: J
authors.lastname: Yin
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.forename: Yong
authors.initials: Y
authors.lastname: Lei
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Xu
authors.forename: Jiande D Z
authors.initials: JD
authors.lastname: Chen
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000494:pharmacology*; D003106:Colon / Q000187:drug effects* / Q000294:innervation / Q000503:physiopathology; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects*; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005772:Gastrointestinal Transit / Q000187:drug effects*; D018589:Gastroparesis / Q000188:drug therapy* / Q000503:physiopathology; D007421:Intestine, Small / Q000187:drug effects* / Q000294:innervation / Q000503:physiopathology; D008803:Mianserin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000078785:Mirtazapine; D011312:Pressure; D012007:Rectum / Q000294:innervation; D013997:Time Factors
chemical_list: D000929:Antidepressive Agents, Tricyclic; D005765:Gastrointestinal Agents; D008803:Mianserin; D000078785:Mirtazapine
keywords: antidepressant; colonic transit; gastric emptying; gastrointestinal motility; rectal distention