Nausea = sensation of the desire to vomit
Vomiting = action of expelling GI contents via mouth (usually an involuntary reflex)

Causes of nausea ​and vomiting in palliative patients

  • Cancer e.g. brain metastasis or bowel obstruction
  • Disease complications e.g. Hypercalcaemia
  • Debility e.g. infection, constipation
  • Treatment e.g. chemotherapy
  • Concurrent e.g. Gastroenteritis

Manag​ement of vomiting

  • Treat underlying cause if possible e.g. infection
  • Determine which neurotransmitter receptors are involved
  • Chose and antiemetic for the specific neuroreceptor
  • Choose the relevant route of administration
  • Reassess to identify any additional triggers

Decide whether any of triggers can be reversed

When the cause of symptoms is known, the antiemetic should be chosen depending on its receptor affinity.  E.g. metoclopramide for treatment of drug side effects.

Dopamine D-2 antagonistHistaminee H-1 antagonistAcetylcholine
(muscarinic) antagonist
5HT2 antagonist5HT3 antagonist5HT4 agonist
metoclopramide++(+)++
domperidone++
cisapride+++
ondansetron+++
cyclizine++++
haloperidol++++
levomepromazine++++++++++

Antiemetic drugs work by binding to specific receptor sites in the chemoreceptor trigger zone (CTZ) or vomiting centre (VC) in the brainstem.  At each site, there are several receptors; the more strongly the drug binds to the receptor, the more potent its antiemetic activity.
Levomepromazine is generally the second line medication used in nausea in palliative care.  It has a broad mechanism of action has good symptomatic relief but many side effects including its action as a sedative.  It can be given by the oral and subcutaneous route.

Non-pharmacological treatments

  • Relaxation techniques
  • Calm treatment
  • Hypnotherapy
  • Small meals/snacks
  • Cover odorous wounds
  • Avoid strong smells e.g. cooking
  • Sea bands/acupressure

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