Quick Tip: Attempt to determine cause by careful evaluation and relevant investigations. Treat reversible causes where possible and appropriate.
Infection: UTI, pneumonia, gastro-enteritis, oropharyngeal candidiasis, meningitis.
Metabolic: Renal impairment, hypercalcaemia, tumour toxins.
Drug-related: Opioids, diuretics, NSAIDs, antibiotics
Chemotherapy and radiotherapy deserve special mention and a specific management plan which is detailed in its own individual section
Gastric stasis causes
Pyloric tumour/nodes, ascites, hepatomegaly, opioids, anticholinergic drugs, autonomic neuropathy, gastritis, ulceration, obstruction, ascites
Obstruction is a cause of gastric stasis which deserves special mention and a specific management plan which is detailed in its own individual section
Organ damage causes
Distension, distortion, obstruction, radiotherapy
Raised intracranial pressure, vestibular disease, motion sickness.
Anxiety, associations of sights/smells.
Table of causes and suggested anti-emetic treatment
Causes and suggested treatment
Information and possible features
Persistent, often severe, nausea unrelieved by vomiting.
Chemotherapy or radiotherapy
Acute: follow oncology guidelines
Combination ondansetron and/or corticosteroids and/or aprepitant
Precipitates release of serotonin
Useful to distinguish between ‘acute’ and ‘delayed’ phase.
Metoclopramide or domperidone
Consider trial of steroids
Fullness/regurgitation, reduced appetite, nausea relieved by vomiting (often large volume and undigested). Functional obstruction (failure of GI motility). Partial bowel obstruction (flatus PR, no colic).
Management detailed in specific section
May be high, low or multiple levels.
High causes regurgitation, forceful vomiting of undigested food. Low causes colicky pain, large volume (possibly faeculent) vomits.
Damage to thoracic, abdominal or pelvic viscera caused by malignancy or treatment.
Raised intracranial pressure/intra-cerebral causes
Headache, visual disturbance, other neurological signs.
Ondansetron / granisetron
Precipitates release of serotonin
Consider non-drug treatment options first. Then benzodiazepine then levomepromazine
E.g., anxiety, fear, anticipation
Consider cyclizine, or haloperidol if chemical cause most likely, or levomepromazine
Terminal phase or patient too ill for investigation
Quick Tip: Commonly used antiemetic drugs are cyclizine, haloperidol, levomepromazine, metoclopramide, more specific and targeted anti-emetics include aprepitant, dexamethasone, domperidone, hyoscine butylbromide, octreotide, olanzepine and ondansetron.
Route and regime
Review – reassess symptom control within 24 hours
Commonly used antiemetic drugs
CYCLIZINE – antihistaminic, anticholinergic anti-emetic.
Some specialists believe that the anticholinergic effects of cyclizine block the action of metoclopramide therefore it is recommended that these two drugs are not combined.
Caution in advanced heart failure and Parkinson’s disease. May cause cognitive impairment/drowsiness.
DOSE: PO/SC: 50mg TDS. Syringe Driver: 150mg/24hrs. If SC use causes skin irritation, dilute to maximum possible volume with water for injection and seek specialist advice if problem persists.
HALOPERIDOL – centrally acting anti-emetic. Most potent D2 antagonist.
Illogical to combine with metoclopramide because both act by central dopamine antagonism. Contra-indicated in Parkinson’s disease.
DOSE: PO/SC: 0.5-3mg ON. Syringe Driver: 0.5-3mg/24hrs. (5mg max dose if necessary).
LEVOMEPROMAZINE - broad spectrum anti-emetic. Consider for refractory/persistent symptoms.
Risk of sedation and hypotension (even at low dose).
Contra-indicated in Parkinson’s disease and Seizures.
If prescribed regularly, give at night. Some specialists recommend very low doses (2.5-5mg) to avoid any risk of sedation.
DOSE: PO/SC: 6.25-25mg ON. Syringe Driver: 6.25-25mg/24 hrs.
METOCLOPRAMIDE - prokinetic and centrally acting anti-emetic.
Some specialists believe the action of metoclopramide is blocked by cyclizine and therefore it is recommended that these drugs are not combined.
Contra-indicated in Parkinson’s disease, complete obstruction and recent GI surgery.
DOSE: PO/SC: 10mg TDS to 20mg QDS. Syringe Driver: 30-60mg/24hrs. Higher doses and long-term use under specialist supervision.
More specific and targeted anti-emetics include:
APREPITANT – a neurokinin receptor antagonist. An adjunct in chemotherapy induced nausea/vomiting.
DOSE: follow oncology advice.
DEXAMETHASONE – corticosteroid. Adjuvant anti-emetic. Stop if no obvious effect within 3-7 days. If continued seek specialist advice due to long term side effects.
DOSE: PO/SC: 4-8mg per day (given before Noon). 16mg initially in raised intracranial pressure.
DOMPERIDONE - prokinetic anti-emetic.
Action blocked by anticholinergic effect of cyclizine: do not combine. Domperidone does not cross blood/brain barrier so avoids extrapyramidal effects of metoclopramide.
DOSE: PO: 10mg TDS. Higher doses and long-term use under specialist supervision as may prolong QT interval with risk of cardiac dysrhythmia.
HYOSCINE BUTYLBROMIDE – antimuscarinic. Reduces GI motility and secretions. Antimuscarinic effect may reduce efficacy of prokinetics. Limited efficacy by mouth – avoid by oral route.
DOSE: SC: 20mg 1-hrly as required up to three doses. Syringe Driver: 60mg-120mg/24hrs.
OCTREOTIDE – somatostatin analogue. Reduces GI secretions.
DOSE: Syringe Driver 250-1000micrograms/24hrs.
OLANZAPINE – centrally active broad-spectrum antiemetic. May be useful in those patients intolerant to haloperidol and/or levomepromazine.
DOSE: Seek specialist palliative care advice.
ONDANSETRON - 5HT3 receptor antagonists. Only recommended post-op and in the acute phase of chemotherapy/radiotherapy treatment. Other indications only under specialist supervision. Can cause severe constipation.
DOSE: follow oncology guidelines. PO/SC: 4-8mg BD-TDS. Syringe Driver 16mg/24hrs.
PCF7 need page numbers