What is the best approach for evaluating and managing intractable nausea and vomiting?

From the Guidelines

The best approach for evaluating and managing intractable nausea and vomiting is to start with a thorough evaluation, including a detailed history, physical examination, and diagnostic tests, and then use a stepwise approach with first-line antiemetics such as ondansetron, metoclopramide, or prochlorperazine, and consider combination therapy or alternative agents for persistent symptoms. When evaluating intractable nausea and vomiting, it is essential to identify the underlying cause while providing symptomatic relief. The evaluation should include:

• A detailed history to determine the onset, duration, and characteristics of the nausea and vomiting
• A physical examination to assess for signs of dehydration, electrolyte imbalances, or other complications
• Diagnostic tests such as blood work, imaging studies, and possibly endoscopy to determine the etiology Management typically involves a stepwise approach, starting with:
• First-line antiemetics such as ondansetron 4-8mg every 8 hours, metoclopramide 10mg three times daily, or prochlorperazine 5-10mg every 6 hours 1
• For persistent symptoms, second-line agents include promethazine 12.5-25mg every 4-6 hours or scopolamine transdermal patch 1.5mg every 72 hours
• In refractory cases, consider combination therapy or alternative agents such as dexamethasone 4-8mg daily, aprepitant 125mg on day one followed by 80mg daily, or haloperidol 0.5-2mg twice daily 1 Ensuring adequate hydration is crucial, often requiring intravenous fluids with electrolyte replacement. Non-pharmacological approaches like small, frequent meals, avoiding trigger foods, and ginger supplements may provide additional benefit. For truly intractable cases, consider consultation with specialists in gastroenterology, neurology, or palliative care, as the underlying cause may require specific treatment beyond symptom management. The effectiveness of antiemetics varies based on the neurotransmitter receptors involved in the specific cause of nausea, which explains why targeting multiple pathways often yields better results in difficult cases 1.

From the FDA Drug Label

In uncontrolled trials, 127 patients receiving cisplatin (median dose, 100 mg/m2) and ondansetron who had two or fewer emetic episodes were re-treated with ondansetron and chemotherapy, mainly cisplatin, for a total of 269 re-treatment courses (median: 2; range: 1 to 10) No emetic episodes occurred in 160 (59%), and two or fewer emetic episodes occurred in 217 (81%) re-treatment courses.

The best approach for evaluating and managing intractable nausea and vomiting is not directly addressed in the provided drug label. However, the label does provide information on the use of ondansetron in preventing nausea and vomiting in patients undergoing chemotherapy or surgery.

• Key points:
  • Ondansetron is effective in preventing nausea and vomiting in patients receiving chemotherapy, particularly those receiving cisplatin.
  • Ondansetron is also effective in preventing postoperative nausea and vomiting in adult and pediatric patients.
• Management:
  • The use of ondansetron may be considered as part of the management strategy for intractable nausea and vomiting, particularly in patients receiving chemotherapy or undergoing surgery.
  • However, the label does not provide specific guidance on the evaluation and management of intractable nausea and vomiting, and other factors such as underlying cause, medical history, and concurrent medications should be taken into account when developing a treatment plan 2.

From the Research

Evaluation of Intractable Nausea and Vomiting

• The evaluation of intractable nausea and vomiting can be challenging due to the numerous possible underlying causes and the vast array of diagnostic and therapeutic options 3.
• A practical 5-step approach to the clinical evaluation and treatment of nausea and vomiting includes defining what the patient means by nausea and vomiting, determining whether symptoms are acute or chronic, considering medication or toxin adverse effects, using the patient's presentation to formulate a differential diagnosis, and directing treatment based on knowledge of neurotransmitters and receptors involved in the emetic pathways 3.
• The initial evaluation and risk stratification of nausea and vomiting involve distinguishing between acute and chronic symptoms, as well as identifying alarm symptoms that may indicate a life-threatening illness 4.

Differential Diagnosis

• The differential diagnosis of nausea and vomiting is broad and can be categorized into gastrointestinal, infectious, metabolic, neurologic, psychiatric, and medication-related causes 4, 5.
• Gastrointestinal causes of chronic nausea and vomiting include gastroparesis, cyclic vomiting syndrome, and other disorders that affect gastric motility and emptying 5.
• Non-gastrointestinal disorders, such as medications, vestibular, and neurologic disorders, can also cause chronic nausea and vomiting 5.

Treatment Options

• The treatment of nausea and vomiting depends on the underlying cause and may involve antiemetic medications, fluid and electrolyte replacement, and nonpharmacologic management options such as small, frequent meals and avoidance of trigger foods 4.
• Antiemetic drugs, such as ondansetron and metoclopramide, can effectively reduce symptoms of acute nausea and vomiting, but chronic symptoms are often more challenging to treat 6, 7.
• A serotonin antagonist or dopamine antagonist can be used when a specific etiology is not identified, but medications may also target the suspected cause of symptoms and the neurotransmitters involved in central and peripheral pathways of nausea and vomiting 3, 4.