Successful Treatment of Gastroparesis with the Antidepressant Mirtazapine: A Case Report

Gastroparesis: A Multidisciplinary Approach to Management

Gastroparesis is a neuromuscular disorder whose hallmark is delayed gastric emptying. It is a global challenge to the healthcare system because of poor treatment satisfaction for both the patients and clinicians, eventually leading to a reduction in the quality of life, with antecedent anxiety and depression. Although it is multifactorial in origin, diabetic, idiopathic, and drug-induced gastroparesis are the major risk factors. Disrupted interstitial cells of Cajal (ICC) and gastric dysrhythmia are pivotal to the pathogenesis, with most of the investigations targeted toward assessing gastric emptying and accommodation usually affected by distorted ICC and other neural networks. The treatment challenges can be overcome by a multidisciplinary approach involving gastroenterologists, gastrointestinal surgeons, biomedical engineers, nutritionists, psychologists, nurses, radionuclide radiologists, pharmacists, and family physicians. The exploration of the fundamental physiological processes underlying gastroparesis with the use of biomechanical materials should be given more attention by biomedical engineers to integrate innovative engineering with medicine for solving complex medical issues.

The Management of Nausea and Vomiting Not Related to Anticancer Therapy in Patients with Cancer

OPINION STATEMENT

In cancer patients, the management of nausea and vomiting that is not directly related to treatment is challenging. Much current practice is based on expert opinion and anecdote. Fortunately, over recent years, a number of quality trials have been undertaken to strengthen the evidence base that guides the care of our patients with these distressing symptoms. Much is still unknown however. In this article, we present the latest literature that addresses some of the outstanding issues.

Mirtazapine for Refractory Gastroparesis

Gastroparesis is a chronic condition of delayed gastric emptying in the absence of mechanical outlet obstruction. We report a 47-year-old African American woman with diabetic gastroparesis who presented with intractable nausea, vomiting, and decreased oral intake with electrolyte disturbances. The patient's symptoms were difficult to control with antiemetic and conventional prokinetic agents, and she was started on mirtazapine 15 mg nightly. She experienced an almost complete symptom relief and was able to tolerate solid food within 24–48 hours. We highlight the role of mirtazapine, a 5-HT_1a agonist, as an effective therapy for refractory gastroparesis.

Chronic nausea and vomiting: evaluation and treatment

Nausea is an uneasy feeling in the stomach while vomiting refers to the forceful expulsion of gastric contents. Chronic nausea and vomiting represent a diverse array of disorders defined by 4 weeks or more of symptoms. Chronic nausea and vomiting result from a variety of pathophysiological processes, involving gastrointestinal and non-gastrointestinal causes. The prevalence of chronic nausea and vomiting is unclear, although the epidemiology of specific conditions, such as gastroparesis and cyclic vomiting syndrome, is better understood. The economic impact of chronic nausea and vomiting and effects on quality of life are substantial. The initial diagnostic evaluation involves distinguishing gastrointestinal causes of chronic nausea and vomiting (e.g., gastroparesis, cyclic vomiting syndrome) from non-gastrointestinal causes (e.g., medications, vestibular, and neurologic disorders). After excluding anatomic, mechanical and biochemical causes of chronic nausea and vomiting, gastrointestinal causes can be grouped into two broad categories based on the finding of delayed, or normal, gastric emptying. Non-gastrointestinal disorders can also cause chronic nausea and vomiting. As a validated treatment algorithm for chronic nausea and vomiting does not exist, treatment should be based on a thoughtful discussion of benefits, side effects, and costs. The objective of this monograph is to review the evaluation and treatment of patients with chronic nausea and vomiting, emphasizing common gastrointestinal causes.

The effect of mirtazapine on gastric accommodation, gastric sensitivity to distention, and nutrient tolerance in healthy subjects

BACKGROUND

Disturbances of gastric motor function of functional dyspepsia (FD) have been implicated in the pathogenesis of the symptoms, and hence, motility modifying agents are considered for its treatment. Mirtazapine was recently shown to improve symptoms and increase nutrient tolerance in FD patients with weight loss. We aim to evaluate the effect of mirtazapine on gastric sensorimotor function in healthy volunteers (HV).

METHODS

Thirty-one HV underwent an intragastric pressure (IGP) and barostat measurements on separate days before and after 3 weeks of placebo or mirtazapine (15 mg). Gastric compliance, sensitivity and accommodation (GA) measured by the barostat. GA was quantitated as the difference (delta) in intra-balloon volume before and after ingestion of 200 mL of a nutrient drink (ND). GA measured by IGP was quantitated as the drop of IGP from baseline during the intragastric infusion of ND until maximal satiation.

KEY RESULTS

Mirtazapine significantly increased the bodyweight of subjects (67.8±3.7 to 69.1±3.7 kg; P=.01). Barostat results showed no effect on gastric compliance, sensitivity, and GA. Nutrient tolerance was not affected after treatment (1170±129.4 vs 1104±133.6 kcal; P=.4), and mirtazapine was associated with lower symptom ratings. The IGP drop during meal ingestion was significantly suppressed (area under the curve: -43.3±4.5 mm Hg vs -28.9±3.1 mm Hg; P=.005).

CONCLUSIONS & INFERENCES

In HVs, the occurrence of weight gain and decreased meal-induced symptoms in spite of a suppressed meal-induced IGP drop, point towards a central mode of action. Mirtazapine does not display changes in gastric sensorimotor function that could explain its beneficial effects on symptoms and nutrient tolerance in FD.

Newest Drugs for Chronic Unexplained Nausea and Vomiting

OPINION STATEMENT

Chronic unexplained nausea and vomiting (CUNV) refers to a symptom complex defined by nausea and/or vomiting with normal diagnostic testing, including anatomic assessments (including upper endoscopy) and measures of upper gut function (e.g., gastric emptying testing). Nausea and vomiting in this condition are postulated to result from aberrant peripheral or central neurohumoral activity. A substantial subset of patients satisfies this diagnosis as more than half of individuals referred for scintigraphic testing exhibit normal gastric emptying rates. No randomized, placebo-controlled trials of any medication treatment have been performed in CUNV. However, agents with potential therapeutic benefits in CUNV include antiemetic drugs, neuromodulatory treatments which are proposed to act by reducing gastric sensitivity, and medications with prokinetic action to stimulate upper gut propulsion. Recently approved drugs with antiemetic capability include serotonin antagonists with novel modes of delivery and neurokinin antagonists with or without additional serotonergic blocking capabilities. Existing neuroleptics and pain-modifying neuromodulatory therapies with fortuitous antiemetic benefits are being considered for their benefits in this disorder. Furthermore, current investigations will define potential therapeutic actions of agents that stimulate gastric emptying via action on gastroduodenal serotonin, motilin, and ghrelin receptors. This current research may broaden the treatment options for refractory cases of unexplained nausea and vomiting.