4.6 Drugs used in nausea and vertigo
Specialist guidance should be referred to for prescribing of anti-emetics in
- cytotoxic chemotherapy
- palliative care
- post-operative nausea and vomiting
Prochlorperazine (5mg tablets, 3mg buccal tablets, 5mg/5mL syrup, 12.5mg/mL injection, 30mg suppositories) is used in the prophylaxis and treatment of drug-induced nausea and vomiting. It may cause extrapyramidal reactions and is mildly sedating. It should not be prescribed to patients with Parkinson's disease and should be used with caution in the elderly.
Metoclopramide (10mg tablets, 5mg/5mL oral solution, 5mg/mL injection) is the preferred agent when sedation is not required. In addition to its effects at the chemoreceptor trigger zone it has a peripheral action on the gut and is therefore contra-indicated for three to four days after gastro-intestinal surgery. Dystonic reactions are most common in the young and very old. Use in patients under 20 years should be restricted to severe intractable vomiting of known cause, vomiting associated with radiotherapy and intolerance to cytotoxic drugs, as an aid to gastrointestinal intubation, and as part of the premedication before surgical procedures. It should not be prescribed for patients with Parkinson's disease.
Severe dystonic reactions to metoclopramide or prochlorperazine should be treated with procyclidine injection.
Aprepitant (capsules, Emend®) is a substrate, a moderate inhibitor, and an inducer of CYP3A4. It is restricted to use in hospital for the prevention of acute and delayed nausea and vomiting associated with highly emetogenic cisplatin-based chemotherapy. Only appropriate hospital-based specialists should initiate it, and use is restricted to very high risk patients and those not controlled with standard emetogenic drugs.
Betahistine (8mg, 16mg tablets) is indicated for vertigo, tinnitus and hearing loss associated with Ménière's disease only.
Cinnarizine (15mg tablets) is indicated for vestibular disorders.
Cyclizine (tablets, suspension, injection) is the drug of choice in palliative care for vestibular-induced vomiting or if gastro-intestinal obstruction is present. In the general population it has the potential for abuse
Dexamethasone (tablets, injection) is as effective for delayed vomiting as the more expensive ondansetron in patients undergoing moderately emetogenic chemotherapy. The combination of dexamethasone and ondansetron may offer advantages in refractory cases.
Domperidone (10mg tablets, 5mg/5mL suspension, 30mg suppositories) resembles metoclopramide but as it does not readily cross the blood-brain barrier it is less likely to cause dystonic reactions. It is used for patients who cannot tolerate metoclopramide, and is the favoured anti-emetic in patients with Parkinson's disease. See Direct Healthcare Professional Communication on domperidone and cardiac safety December 2011, MHRA Drug Safety Update May 2012.
Haloperidol (tablets, capsules, oral liquid, injection) is the drug of choice for opioid-induced vomiting in palliative care.
Hyoscine hydrobromide (tablets, injection, patches) is very effective in the prevention of motion sickness. It has other specialised uses in surgery and palliative care.
Levomepromazine (tablets, injection) is used in palliative care.
Ondansetron (tablets, injection) is a 5HT3 antagonist. It is extremely expensive compared to other antiemetics. Its use in hospital is restricted to chemotherapy with highly emetogenic regimens and wide field abdominal irradiation. It is also second-line in post-operative nausea and vomiting where prochlorperazine/cyclizine is not effective, and in ECT where vomiting is a problem.
PRESCRIBING POINTS FOR DRUGS USED IN NAUSEA AND VERTIGO
- The underlying cause of nausea should be identified and treated before starting treatment with an anti-emetic whenever possible, otherwise their use may delay diagnosis.
- Dopamine antagonists such as prochlorperazine and metoclopramide can induce acute dystonic reactions with facial and skeletal muscle spasms and oculogyric crisis. This usually occurs shortly after starting treatment and is more common in the young (especially girls and young women) and the very old. This reaction is rapidly abolished by intravenous administration of procyclidine.
- Long-term use of metoclopramide may cause tardive dyskinesia in the elderly.
- Ondansetron should be used according to local guidelines only.
- Nausea in the first trimester of pregnancy does not normally require drug therapy. Cyclizine or promethazine may be tried for up to 48 hours if vomiting is severe. If symptoms do not settle specialist advice should be sought, see NICE CG62 http://publications.nice.org.uk/antenatal-care-cg62.
- Surgical patients receiving opioids should be prescribed prophylactic anti-emetics such as cyclizine or prochlorperazine.
- Patients suffering an acute myocardial infarction should be given intravenous morphine and metoclopramide concomitantly. Cyclimorph® (containing morphine and cyclizine) is an alternative but repeated doses are not recommended.