Antiemetics

The evidence base to support prescribing of antiemetics in advanced cancer and other palliative conditions is not well developed, and much of the existing knowledge relates to chemotherapy induced nausea and vomiting, which involves a well defined 'emetic pathway'. The physical causes in palliative care patients are likely to be more complex.

The main classes of antiemetics are:

  • Dopamine antagonists (eg, metoclopramide, haloperidol, domperidone, levomepromazine, other antipsychotics)
  • Antihistamines (eg, cyclizine, promethazine) 
  • Serotonin (5HT3) antagonists (eg, ondansetron, tropisetron, granisetron) 
  • Other agents (eg, anticholinergics, steroids, neurokinin-1 antagonists, benzodiazepines for anticipatory nausea).

Choosing antiemetics based on the presumed mechanism of the symptoms (55kb pdf) and the inferred neurotransmitter pathways thought to be involved in each mechanism, is a standard approach in palliative care. The effectiveness of this approach has been investigated in several small studies. [1,2] However the lack of strong evidence regarding the underlying assumptions means that antiemetic choices are still, in practice, derived mainly from expert opinion. [3]

What is known 

  • There is some evidence that metoclopramide is effective in advanced cancer, and it is the best studied antiemetic in this setting. [3] It had a 75% response rate when used for chronic nausea thought to be due to gastroparesis. [4]  
  • There is evidence to support the effectiveness of serotonin antagonists in palliative care, however there are concerns over cost and side effects (constipation in particular). [3] A randomised controlled trial that is currently under way will help to clarify these issues. 
  • Many antiemetics are commonly in use off-license in palliative care, such as: 
    • Cyclizine (an antihistamine available via the Special Access Scheme)
    • Corticosteroids 
    • Methotrimeprazine / levomepromazine (a broad spectrum antipsychotic available via the Special Access Scheme).
      They are likely to be effective, although the research supporting their use is not extensive. [3]

Implications for practice

  • Antiemetics that can be given by the subcutaneous route if nausea or vomiting are uncontrolled are used in palliative care for practical reasons.
  • Prochlorperazine is not as frequently used because it is unsuitable for the subcutaneous route.
  • Inferences about the main mechanism of nausea can be used to guide choice of antiemetic according to receptor profile in most instances.
  1. Lichter I. Results of antiemetic management in terminal illness. J Palliat Care. 1993 Summer;9(2):19-21.
  2. Bentley A, Boyd K. Use of clinical pictures in the management of nausea and vomiting: a prospective audit. Palliat Med. 2001 May;15(3):247-53.
  3. Glare P, Pereira G, Kristjanson LJ, Stockler M, Tattersall M. Systematic review of the efficacy of antiemetics in the treatment of nausea in patients with far-advanced cancer. Support Care Cancer. 2004 Jun;12(6):432-40. Epub 2004 Apr 24.
  4. Bruera E, Belzile M, Neumann C, Harsanyi Z, Babul N, Darke A. A double-blind, crossover study of controlled-release metoclopramide and placebo for the chronic nausea and dyspepsia of advanced cancer. J Pain Symptom Manage. 2000 June;19(6):427-35.
  5. Critchley P, Plach N, Grantham M, Marshall D, Taniguchi A, Latimer E, et al. Efficacy of haloperidol in the treatment of nausea and vomiting in the palliative patient: a systematic review. J Pain Symptom Manage. 2001 Aug;22(2):631-4.  No abstract available.
  6. Flake ZA, Scalley RD, Bailey AG. Practical selection of antiemetics. Am Fam Physician. 2004 Mar 1;69(5):1169-74. 

Overview article

Guidelines

Link to prescribing information

Last updated 18 January 2017