Refractory nausea and vomiting in palliative care
Some cases of nausea and vomiting do not respond to a single antiemetic; for example, if the cause of nausea and vomiting is multifactorial, or when a single emetic stimulus is very strong (eg highly emetogenic chemotherapy, bowel obstruction).
For refractory nausea and vomiting, multiple drugs can be tried as single drugs given sequentially, or they can be given in combination. When combining drugs, target different elements of the emetogenic process, or different chemoreceptors. Avoid combining dopamine antagonists such as metoclopramide, prochlorperazine and haloperidol because this will increase the risk of a dystonic reaction.
A corticosteroid, in combination with other antiemetics, can be tried for refractory nausea and vomiting in patients with palliative care needs. Seek oncology or haematology advice if a corticosteroid is considered because corticosteroids may interfere with some treatments or tissue diagnosis. Use:
dexamethasone 4 mg orally, daily. Assess within 3 days and stop if there is no benefit. If there is benefit, reduce to the lowest effective dose and use for the shortest possible time. For advice on stopping dexamethasone, see Rationalising corticosteroids used for symptom or complication management in palliative care. dexamethasone
If the above therapy for refractory nausea and vomiting is ineffective, seek specialist palliative care advice; treatment options include cyclizine, levomepromazine, olanzapine and cannabinoidsHardy, 2021Hardy, 2019.