Nausea and Vomiting Flashcards
How are antiemetics chosen?
History, examination and investigations to determine the cause
Non pharmacological treatments for N&V
- avoid triggers
- Make sure that meals are small and palatable
- cold fizzy drinks
- Ginger (esp in pregnancy)
- eating little and often
- Bland foods (carbs- biscuits, toast)
How to treat toxicity-related nausea and vomiting from drug-induced or metabolic upset
- Haloperidol- 1.5mg at night or BD
oral or subcut - Metoclopramide- 10mg QDS
subcut or oral - Levomepromazine
Subcut
How to treat movement-related nausea and vomiting?
- Cyclizine- 25-50mg every 8 hours.
oral or subcut - Hyoscine hydrobromide: 150–300 micrograms orally,
oral, subcutaneously, transdermal patch (1mg/72 hours) - Cinnarizine: 30 mg orally initially then 15 mg three times a day.
- Levomepromazine: 3–6 mg twice daily (PO)
oral, subcutaneous injection or infusion - Prochlorperazine: 3 mg buccal or 5–15 mg oral.
Examples of antihistamines used in N&V
cyclizine, promethazine (hydrobromide and teoclate), cinnarazine
How to phenothiazines treat N&V
Dopamine antagonists and block the chemoreceptor trigger zone.
What is the least sedative phenothiazine
prochlorperazine
Which antiemetic directly acts on the GI tract
Metoclopromide
Examples of 5HT3 antiemetics?
Ondansetron and Granisetron
MoA of Domperidone
dopamine antagonist and blocks the chemoreceptor trigger zone.
When are 5HT3 antagonists used in N&V
following cytotoxics
What’s 1st and 2nd for N&V in pregnancy?
1st- Self care advice- rest, oral rehydration & dietary changes
2nd- Non-pharmacological treatment Ginger
What antiemetics are safe in pregnancy?
C2OMP3
C- cyclizine and chlorpromazine
O- ondansetron
M- metoclopramide
P- prochlorperazine, promethazine hydro and teoclate (caution in 3rd tri)
What are the first line treatment options for N&V in pregnancy?
- oral cyclizine or promethazine (antihistamines),
- prochlorperazine or chlorpromazine (phenothiazines),
- combination drug doxylamine/pyridoxine (Xonvea®) first-line
What are the second line treatment options for N&V in pregnancy?
oral metoclopramide or domperidone or ondansetron
What antiemetics are given for motion sickness
- give preventatives hyoscine hydrobromide or
- promethazine (sedation required) or cyclizine/cinarizine (less sedating required)
What antiemetics should be ineffective for the treatment of motion sickness
domperidone, 5HT3 antagonist, metoclopramide, phenothiazines.
What phenothiazine can be given for motion sickness
prochlorperazine
How to treat post operative N&V
combo of 2 or more antiemetics:
- 5HT3 (ondansetron)
- Dexamethasone
- Doperidol and haloperidol
- Prochlorperazine
- Cyclizine
Licensing for prochlorperazine for post-op N&V
prevention and treatment
Licensing for cyclizine for post-op N&V
prevention and treatment N&V caused by opioids or general anaesthesia
What is Menieres disease?
Condition of the inner ear that causes sudden attacks of vertigo and tinnitus.
Medications used in Menieres disease
Betahistine- Vertigo and tinnitus associated
antihistamines- cinnarzine
phenothiazine- prochlorperazine –> should only be used for acute symptoms
Domperidone safety advice
Risk of cardiac side effects. Report symptoms of arrhythmia (palps or syncope)
What’s the maximum treatment duration for domperidone
7 days
Metoclopramide safety advice
risk of neurological adverse effects
what’s the recommended treatment duration for metoclopramide
up to 5 days
Promethazine MHRA advice
Not to be sold OTC for children under 6.
At what age is promethazine contraindicated?
2 years
potential for fatal respiratory depression
