nausea & vomiting

Question 1

antihistamines

Answer 1

antihistamines (cinnarizine, cyclizine, promethazine) useful in prophylaxis and treatment of n&v

Question 2

phenothiazines

Answer 2

phenothiazines - dopamine antagonists - act centrally by blocking chemoreceptor trigger zone

prochlorperazine - useful in prophylaxis and treatment of n&v

can cause severe dystonic reactions (EPSE) esp in children

can be used in chemotherapy/radiation induced n&v

Question 3

palliative care

Answer 3

antipsychotics such as haloperidol or levomepromazine used for relief of n&v in palliative care pts

Question 4

metoclopramide

Answer 4

effective anti-emetic

activity resembles phenothiazines

also acts directly on gastric smooth muscle - stimulates gastric emptying

can be used for emesis associated with GI/biliary disease

10mg TDS

minimum age 18 years

max use 5 days

causes EPSE - do not use in Parkinson’s

Question 5

domperidone

Answer 5

acts at chemoreceptor trigger zone

advantage over phenothiazine and metoclopramide as doesn’t cause central effects like sedation, dystonic reactions - doesn’t cross BBB readily

low dose domperidone can be used in parkinson pts who develop n&v due to dopaminergic drugs

10mg TDS

minimum age 12 years

max use - 7 days

weight 35kg+

causes QT prolongation

Question 6

5-HT3 antagonists

Answer 6

granisetron, ondansetron, palonosetron

used in management of n&v in pts receiving cytotoxics

Question 7

dexamethasone

Answer 7

used in management of chemotherapy-induced n&v

can be used alone or in combination with 5HT3 antagonists

Question 8

neurokinin-1 receptor antagonists

Answer 8

aprepitant, fosaprepitant

used in chemotherapy-induced n&v

usually used in combination with dexamethasone and HT3 antagonist

Question 9

nabilone

Answer 9

synthetic cannabinoid

used as add-on therapy in chemotherapy-induce n&v when optimised conventional antiemetic treatment hasn’t worked

specialist

Question 10

anti-emetics in pregnancy, post-operative, pre-operative anticipatory, motion sickness, terminal illness, parkinson’s

Answer 10

pregnancy - avoid drug therapy, self care (rest, hydration) - use promethazine if needed

post-operative - ondansetron or dexamethasone

pre-operative - lorazepam

motion sickness - hyoscine hydrobromide

terminal illness - antipsychotics (haloperidol, levomepromazine)

parkinson’s - domperidone