1. Management of Nausea & Vomiting
Dr Iain Lawrie
Specialist Registrar
in Palliative Medicine

2. Chemoreceptor Trigger Zone
Vomit
Vomiting Centre
Cortical Structures
Gut Mucosa
Vestibular Apparatus
D2 5-HT3 ACh
H1 5-HT2 ACh
Chemoreceptor Trigger Zone
D2 5-HT3 Ach
H1, ACh

3. Chemoreceptor Trigger Zone
Vomit
Vomiting Centre
Cortical Structures
Gut Mucosa
Vestibular Apparatus
D2 5-HT3 ACh
H1 5-HT2 ACh
H1 ACh
Motion
Emotions, sights, smells, raised ICP
GI obstruction, bowel colic, tumour mass, constipation
Chemoreceptor Trigger Zone
Drugs, toxins, uraemia, hypercalcaemia

4. Chemoreceptor Trigger Zone
Vomit
Vomiting Centre
Cortical Structures
Gut Mucosa
Vestibular Apparatus
D2 5-HT3 ACh
H1 5-HT2 ACh
H1 ACh
Motion
Emotions, sights, smells, raised ICP
GI obstruction, bowel colic, tumour mass, constipation
Chemoreceptor Trigger Zone
Drugs, toxins, uraemia, hypercalcaemia
Metoclopramide, Levomepromazine Granisetron
Haloperidol Metoclopramide Levomepromazine Granisetron
Dexamethasone
Cyclizine, Hyoscine HBr
Cyclizine, Levomepromazine, Hyoscine HBr

5. Factors to consider Mechanism of action of anti-emetic drugs
Response to anti-emetics already given
Combinations of drugs should have different actions
Levomepromazine has multiple receptor affinities

6. Factors to consider
Effects of anti-emetics on GI motility (prokinetic / antikinetic)
Adjuvant use of anti-secretory drugs
Adjuvant use of corticosteroids
Adverse effects of drugs
Cost of drugs

7. Management Correct reversible causes ­ stop gastric irritant drugs
­ treat gastritis
• PPIs / antacids
­ treat cough
• antitussive
­ treat constipation
• laxatives

8. Management Raised ICP - steroids / radiotherapy Anxiety Hypercalcaemia
- rehydration +/- bisphosphonates

9. Causes of drug-induced N&V
Gastric irritation
Gastric stasis
CTZ stimulation
5HT3-receptor stimulation
Antibiotics, iron, NSAIDs
Antimuscarinics, opioids, TCA
Antibiotics, cytotoxics, digoxin
Antibiotics, cytotoxics, SSRIs

10. What if it’s not working?
Is it being absorbed?
Is the dose optimum?
Do you have the correct cause?
Most anti-emetics can be given SC
Doses usually the same PO, SC and IV

11. Prescribing an anti-emetic
Choice depends on cause of N&V
Give regularly
Alternative to oral route if unable to absorb
- subcutaneous stat doses
- continuous subcutaneous infusion (driver)
- rectal route

12. Anti-emetics – dopamine antagonists
Haloperidol (D2)
Metoclopramide (D2, 5-HT3, 5-HT4 agonist)
Prochlorperazine (D2)
Domperidone (D2)
Levomepromazine (D2, ACh, H1, 5-HT3)
Side effects
- EPSE
- sedation in higher doses
- reduce seizure threshold

13. Anti-emetics – histamine antagonists
Cyclizine (H1, ACh)
Levomepromazine (D2, ACh, H1, 5-HT3)
Side effects
- drowsiness
- anticholinergic effects
- postural hypotension

14. Anti-emetics - anticholinergics
Hyoscine butylbromide (ACh)
Hyoscine hydrobromide (ACh)
Cyclizine (ACh)
Levomepromazine (D2, ACh, H1, 5-HT3)
Side effects
- sedation
- anticholinergic effects

15. Anti-emetics - prokinetics
Metoclopramide (D2, 5-HT3, 5-HT4 agonist)
Domperidone (D2)
Side effects:
- colic
- EPSE (not domperidone – doesn’t cross BBB)

16. Anti-emetics – serotonin antagonists
Ondansetron, granisetron, tropisetron
Side effects
- constipation
Place in palliative care
- obstruction / stretch
- resistant N&V

17. Anti-emetics - steroids
Dexamethasone
Reduce permeability of BBB & area postrema to emetogenic substances
Reduce neuronal content of GABA in the brain stem
Reduce leuenkephalin release
Reduce oedema around lesion or tumour

18. Gastric stasis & irritation
Nausea made worse by eating
Large volume vomits
Early fullness & bloating
Belching & reflux
Hiccups
Epigastric fullness & tenderness

19. Gastric stasis & irritation
1st line metoclopramide
Adjuncts
- antiflatulent
- PPI
- stop irritant drugs

20. Bowel obstruction without colic
Variable nausea
Vomiting dependent on site of obstruction
Abdominal distension
Background aching pain
Constipation
Absent or ‘hyperactive’ bowel sounds

21. Bowel obstruction without colic
1st line metoclopramide
2nd line cyclizine or haloperidol (substitute)
Adjuvants
- diamorphine
- octreotide
- docusate
- steroids

22. Bowel obstruction with colic
Symptoms as before, but with colicky pains
1st line cyclizine OR haloperidol PLUS buscopan
2nd line cyclizine AND haloperidol OR levomepromazine
Adjuvants
- diamorphine, octreotide, docusate

23. Chemical induced N&V Significant nausea Variable vomiting
Few other GI symptoms
Evidence of presence
i.e. new drug started, biochemistry results
1st line haloperidol / metoclopramide
2nd line ADD cyclizine OR substitute levomepromazine

24. Raised intracranial pressure
Known intracerebral tumour
Early morning headaches
Predominant nausea
Intermittent vomiting
Papilloedema
Neurological deficit
Seizures

25. Raised intracranial pressure
1st line dexamethasone & cyclizine
2nd line ADD haloperidol
3rd line 5-HT3 antagonist (substitute)

26. Motion / movement related N&V
Nausea & vomiting worse on movement
Can be associated with cranial nerve lesions and base of skull metastases
1st line cyclizine
2nd line hyoscine hydrobromide

27. Indeterminate N&V 1st line haloperidol OR cyclizine
2nd line haloperidol AND cyclizine
3rd line levomepromazine (substitute)
4th line consider metoclopramide, dexamethasone, 5HT3 antagonist

28. Summary Try to determine the cause wherever possible
1/3 of patients will need more than one anti-emetic
Eliminate reversible causes
Continue anti-emetic indefinitely if cause is not self-limiting