Gastroparesis: Treatment (part 2)

Initial management of gastroparesis often focuses on treating dehydration and electrolyte and nutritional deficits.  One study found that 64% of gastroparesis patients were not consuming enough daily calories to support the needs of their bodies, which can worsen symptoms.  Vitamins A, B6, C, and K, as well as iron, potassium and zinc are frequently deficient in this population.  Small meals low in fat and fiber are recommended for gastroparesis patients.  Liquids or blended solids often empty normally from the stomach.

For cases in which oral diet is unable to provide sufficient calories and nutrition, placement of a feeding tube may be necessary.  Jejunal feeding tubes are often used successfully.  Prior to surgical placement of a feeding tube, a nasojejunal tube should be used successfully.  PEG-J or Jet-PEG tubes allow venting of gastric secretions to reduce vomiting and nausea while providing a feeding route.

TPN (total parental nutrition) is given intravenously, but carries risks, including central line infections.  For patients in whom oral feeding is not feasible, a feeding tube is often considered the safer option.

Metoclopramide, a dopamine D2 receptor antagonist, is approved for treatment of gastroparesis.  However, treatment beyond 12 weeks should be considered only if the improvement on this medication is significant enough to outweigh risks.  Metoclopramide can cause dystonia and tardive dyskinesia.  Benzodiazepines and antihistamines are sometimes used to treat these side effects.  Domperidone is also a dopamine D2 receptor antagonist, but has lower incidence of side effects.  It is not approved in the US, but can be obtained via special FDA approval for US patients.

Medications to increase gastric motor activity, like erythromycin, are often used in gastoparesis patients.  When taken orally, erythromycin often becomes less effective after several weeks of relief.  Proton pump inhibitors and H2 antihistamines may provide some relief as gastroparesis is often associated with and irritating to GERD.

Medications for management of nausea and vomiting are mainstays for many gastroparesis patients, with phenothiazines or antihistamines often used for this purpose.  5-HT3 receptor antagonists like ondansetron are also widely used.  The neurokinin receptor-1 antagonist aprepitant is sometimes used after failing other antiemetics.  Scopolamine patches and dronabinol are also options.  Tricyclic antidepressants can be used to manage nausea, vomiting and abdominal pain, with nortriptyline and desipramine often preferred over amitriptyline, which can cause delayed emptying.  Mirtazapine has been reported as successful in a case study.

Abdominal pain associated with gastroparesis can be difficult to manage because opiates can induce gastroparesis.  Gabapentin, tramadol, tapentadol, pregabalin and nortriptyline are non-opiate options for pain management.

For some patients, more invasive treatment is indicated.  Some patients with gastroparesis have increased tone in the pyloric canal, which can contribute to delayed gastric emptying.  Injection of botulinum toxin (Botox) into the pyloric sphincter is sometimes tried.  In double-blind studies, use of Botox increases gastric emptying but does not improve symptom profiles.

There are surgical options to manage gastroparesis, with varying results.  Gastric electrical stimulation is considered for patients with long term symptoms that have not improved despite treatment.  These devices are implanted and provide low grade electrical stimulation to the stomach and increase motility.  In diabetic gastoparesis patients, this method improved quality of life and decreased symptoms.  Patients who acquired gastroparesis following surgery, or whose gastroparesis is idiopathic, were less likely to improve using GES.  Pyloroplasty and gastrectomy (partial or complete) have been trialed in some patients, but there is not a clear trend in the data.

Acupuncture has been shown to benefit gastroparesis patients in a number of studies, including one blinded, randomized study. Symptom severity was improved in those receiving acupuncture and gastric emptying time was decreased.  Autogenic retraining using the program developed by NASA for space motion sickness has shown some benefit.  Autogenic retraining was found to be more successful in patients with intact autonomic function.

References:

Sarosiek, Irene, et al. Surgical approaches to treatment of gastroparesis: Gastric electrical stimulation, pyloroplasty, total gastrectomy and enteral feeding tubes.  Gastroenterol Clin N Am 44 (2015) 151-167.

Pasricha, Pankaj Jay, Parkman, Henry P. Gastroparesis: Definitions and Diagnosis. Gastroenterol Clin N Am 44 (2015) 1-7.

Parkman, H. P. Idiopathic Gastroparesis. Gastroenterol Clin N Am 44 (2015) 59-68.

Nguyen, Linda Anh, Snape Jr., William J. Clinical presentation and pathophysiology of gastroparesis.  Gastroenterol Clin N Am 44 (2015) 21-30.

Bharucha, Adil E. Epidemiology and natural history of gastroparesis. Gastroenterol Clin N Am 44 (2015) 9-19.

Camilleri, Michael, et al. Clinical guideline: Management of gastroparesis. Am J Gastroenterol 2013; 108: 18-37.