Basics

Management

Nausea and vomiting in palliative care is often multi-factorial, however it is still important to identify the most prominent cause in order to guide choice of anti-emetic therapy. Six potential syndromes have been identified in palliative care, with gastric stasis and chemical disturbance being the most common and prominent.

Six broad nausea and vomiting syndromes

• Reduced gastric motility
  • May be opioid related
  • Related to serotonin (5HT4) and dopamine (D2) receptors
• Chemically mediated
  • Secondary to hypercalcaemia, opioids, or chemotherapy
• Visceral/serosal
  • Due to constipation
  • Oral candidiasis
• Raised intra-cranial pressure
  • Usually in context of cerebral metastases
• Vestibular
  • Related to activation of acetylcholine and histamine (H1) receptors
  • Most frequently in palliative care is opioid related
  • Can be motion related, or due to base of skull tumours
• Cortical
  • May be due to anxiety, pain, fear and/or anticipatory nausea
  • Related to GABA and histamine (H1) receptors in the cerebral cortex

In palliative care, pharmacological therapy is the usually the first-line method for treating nausea and vomiting. In general, there are two approaches to choosing drug therapy, either empirical or mechanistic. An empirical approach involves choosing medication based on either physician preference or commonly a dopamine antagonist (e.g. metoclopramide) is used first-line. Alternatively, the mechanistic approach utilises matching choice of anti-emetic drug to the likely cause of the patient's nausea and vomiting.

Mechanistic approach

• Reduced gastric motility
  • Pro-kinetic agents are useful in these scenarios as the nausea and vomiting is usually resulting from gastric dysmotility and stasis
  • According to BMJ best practice, first-line medications include metoclopramide and domperidone
  • However, NICE indicate that metoclopramide should not be used when pro-kinesis may negatively affect the gastrointestinal tract, particularly in complete bowel obstruction, gastrointestinal perforation, or immediately following gastric surgery
• Chemically mediated
  • If possible, the chemical disturbance should be corrected first
  • In the context of other chemically mediated syndromes, for example due to opioid medications, there are a number of suggested medications
  • Key treatment options include ondansetron, haloperidol and levomepromazine
• Visceral/serosal causes
  • Cyclizine and levomepromazine are first-line
  • Anti-cholinergics such as hyoscine can be useful
• Raised intra-cranial pressure
  • Cyclizineis recommended first-line for nausea and vomiting due to intracranial disease
  • Dexamethasone can also be usd
  • Radiotherapy can be considered if there is likely raised intra-cranial pressure due to cranial tumours
• Vestibular
  • BMJ best practice recommends use of cyclizine as a first-line treatment in disorders due to the vestibular system
  • Refractory vestibular causes of nausea and vomiting can be treated alternatively with metoclopramide or prochlorperazine
  • Atypical antipsychotics such as olanzapine or risperidone can be used in refractory cases according to UptoDate
• Cortical
  • If anticipatory nausea is the clear cause, a short acting benzodiazepine such as lorazepam can be useful
  • If benzodiazepines are not ideal, BMJ best practice recommends use of cyclizine
  • Ondansetron and metoclopramide can also be trialled