Palliative Care - Nausea and Vomiting

Question 1

Cyclizine is used in palliative care for nausea in which scenarios?

Answer 1

Mechanical bowel obstruction

Raised intracranial pressure

Question 2

When is Ondansetron used for nausea?

Answer 2

5-HT3 receptor antagonist

Used for nausea secondary to chemotherapy

Question 3

When is Dexamethasone used in palliative care as an anti-emetic?

Answer 3

In cases where there is raised intracranial pressure

Question 4

What are the 6 main causes of nausea and vomiting in palliative care and what are examples for each?

Answer 4

1. Reduced gastric motility - may be opioid related
2. Chemically mediated - hypercalcaemia, opioids, or chemotherapy
3. Visceral/serosal causes - due to constipation, or oral candiasis
4. Raised intra-cranial pressure - usually in context of cerebral metastases
5. Vestibular - opioid related, motion related, base of skull tumours
6. Cortical - anxiety, pain, fear and/or anticipatory nausea

Question 5

In reduced gastric motility scenarios, what drugs are used for N+V?

Answer 5

first-line medications include metoclopramide and domperidone

Question 6

When shouldn’t you use metoclopramide for N+V in reduced gastric motility scenarios?

Answer 6

If extrapyramidal effects are a problem with metoclopramide, use domperidone

complete bowel obstruction

gastrointestinal perforation

immediately following gastric surgery

Question 7

In chemically-mediated scenarios, what drugs are used for N+V?

Answer 7

• If possible, the chemical disturbance should be corrected first
• Key treatment options include haloperidol, ondansetron and levomepromazine

Question 8

In visceral/serosal scenarios, what drugs are used for N+V?

Answer 8

• 1st LINE - Cyclizine and levomepromazine
• Anti-cholinergics such as hyoscine can be useful

Question 9

In raised intra-cranial pressure scenarios, what drugs are used for N+V?

Answer 9

• Cyclizine
• Dexamethasone
• Radiotherapy - if likely raised intra-cranial pressure due to cranial tumours

Question 10

In vestibular scenarios, what drugs are used for N+V?

Answer 10

1st LINE - Cyclizine in disorders due to vestibular system

Refractory vestibular causes - metoclopramide or prochlorperazine

Question 11

In cortical scenarios, what drugs are used for N+V?

Answer 11

• If anticipatory nausea is the clear cause, a short acting benzodiazepine such as lorazepam
• Benzodiazepines not ideal, BMJ best practice recommend cyclizine

Question 12

What is first line anti-emetic for the 6 main causes of nausea in palliative care?

Answer 12

1. Reduced gastric motility - metoclopramide and domperidone
2. Chemically mediated - haloperidol, levomepromazine, ondansetron
3. Visceral/serosal causes - Cyclizine and levomepromazine
4. Raised intra-cranial pressure - Cyclizine
5. Vestibular - Cyclizine
6. Cortical - Lorazepam

Question 13

What receptors is vestibular nausea related to?

Answer 13

• Related to activation of acetylcholine and histamine (H1) receptors

Question 14

What receptors is cortical nausea related to?

Answer 14

• Related to GABA and histamine (H1) receptors in the cerebral cortex

Question 15

What receptors is reduced gastric motility related to?

Answer 15

• Related to serotonin (5HT4) and dopamine (D2) receptors

Question 16

What route of anti-emetic is most preferable?

Answer 16

Oral anti-emetics are preferable when not contraindicated?

Question 17

When would oral anti-emetics be contraindicated/undesirable?

Answer 17

1. Patient is vomiting
2. Issues with malabsorption
3. Severe gastric stasis