GI - nausea + vomit e-book

Question 1

Causes of nausea and vomiting

Answer 1

 Postoperative nausea and vomiting (PONV)
 Chemotherapy induced nausea and vomiting
 Drug induced nausea and vomiting
 Motion sickness
 Pregnancy
 Migraine
 Palliative care

Question 2

There are several classes of antiemetic drugs;

Answer 2

 Antihistamines
 Dopamine antagonists
 Antimuscarinics
 5HT3 antagonists
 Neurokinin receptor antagonists

Question 3

Antihistamines e.g cyclizine, cinnarizine, promethazine

Answer 3

These are effective against nausea and vomiting resulting from many underlying conditions.
Side effects;
 Drowsiness
 Anticholinergic effects- blurred vision, constipation, dry mouth, urinary retention.
 Angle-closure glaucoma
 Bronchospasm

Question 4

Cyclizine

forms, indication, dosage

Answer 4

 Available for oral, intramuscular, intravenous or subcutaneous administration
Licensed indications
 Motion sickness
 Labyrinthine disorders
 Nausea and vomiting of known cause
 Nausea and vomiting associated with vestibular disorders
 Palliative care

Dosage in adults; 50mg up to three times a day (for all routes of administration)
In palliative care a dose of 150mg can be given via subcutaneous infusion in a syringe driver over 24
hours.

Question 5

Cinnarizine

forms, indication, dosage

Answer 5

 Available orally only

Licensed indications
 Relief ofsymptoms of vestibular disorders
 Motion sickness

VD = Adults or children over 12 30mg three times daily
MS = 30mg initially 2 hours before travel and then 15mg every 8 hours if required, dose to be taken during travel

Question 6

Promethazine

forms, indication, dosage

Answer 6

 Available orally only

Licensed indications
 Labyrinthine disorders
 Motion sickness

MS = 25mg daily
LD = 25-75mg daily, max 100mg daily

Question 7

Dopamine antagonists- phenothiazines, domperidoneand metoclopramide
Phenothiazines, e.g. prochlorperazine, perphenazine, trifluoperazine

Answer 7

Act centrally on the chemoreceptor trigger zone, these drugs are useful for the treatment of N&V
associated with diffuse neoplastic disease, radiation sickness, and emesis caused by drugs such as
opioids, general anaesthetics, and cytotoxics.
Side effects;
 Dystonic reactions-resulting from Dopamine antagonism
 Hypotension
 Respiratory depression in susceptible patients
 Sedation

Question 8

Prochlorperazine

forms, indication, dosage

Answer 8

Available for oral, buccal, intramuscular
Licensed indications
 Acute attack of nausea and vomiting: Initially 20mg then 10mg after 2 hours. IM 12.5mg as required to be followed by an oral dose after 6h if required
 Prevention of nausea and vomiting: 5-10mg 2-3 times daily. IM 12.5mg as required to be followed by an oral dose after 6h if required
 Labyrinthine disorders: 5mg 3 times a day increased to 30mg daily in divided doses
 Nausea and vomiting in previously diagnosed migraine: 3-6mg bd (bucal tab)

Question 9

Perphenazine

forms, indication, dosage

Answer 9

Only licensed for severe nausea and vomiting unresponsive to other antiemetics.

initially 4mg 3 times a day, max 24mg daily
elderly: initially 1-2mg 3 times a day, max 12mg daily

Question 10

Trifluoperazine

forms, indication, dosage

Answer 10

Only licensed for severe nausea and vomiting
Note- perphenazine and trifluoperazine are not commonly used in the management of nausea and
vomiting.

severe nausea and vomit: 2-4mg in daily divided doses, 6mg max daily

Question 11

Domperidone

forms, indication, dosage

Answer 11

Only licensed for the relief of nausea and vomiting.
Contraindicated in patients with cardiac disease.
Domperidone used to be very widely used however after the benefits and risks of domperidone were
reviewed the MHRA/CHMproduced the following advice as it was found to be associated with a small
increased risk of serious cardiac side effects.
 Domperidone should only be used for the relief of the symptoms of nausea and vomiting;
 Domperidone should be used at the lowest effective dose for the shortest possible duration
(max. treatment duration should not normally exceed 1 week);
 Domperidone is contra-indicated for use in conditions where cardiac conduction is, or could be impaired, or where there is underlying cardiac disease, when administered concomitantly with
drugs that prolong the QT interval or potent CYP3A4 inhibitors, and in severe hepatic
impairment
However, note that this guidance does not apply to unlicensed uses of domperidone, e.g. in palliative
care.

dosage = Adult >35kg - 10mg up to 3 times daily, 30mg max
Child up to 35kg - 250micrograms/kg up to 3 times, max 750mcg/kg

Question 12

Metoclopramide

forms, indication, dosage

Answer 12

 Available for oral, intramuscular, intravenous or subcutaneous administration
Licensed indications
 Symptomatic treatment of nausea and vomiting
 Nausea and vomiting associated with acute migraine
 Chemotherapy induced nausea and vomiting
 Post-operative nausea and vomiting

Metoclopramide used to be widely used however after the benefits and risks of its use were reviewed
the MHRA/CSM produced the following guidance after it was found that the risk of neurological effects
such as extrapyramidal disorders and tardive dyskinesia outweigh the benefits in long term o high dose
treatment. To help minimise the risk of potentially serious neurological adverse effects the following
restrictions apply;
 in adults over 18 years, metoclopramide should only be used for prevention of postoperative
nausea and vomiting, radiotherapy-induced nausea and vomiting, delayed (but not acute)
chemotherapy-induced nausea and vomiting, and symptomatic treatment of nausea and vomiting, including that associated with acute migraine (where it may also be used to improve
absorption of oral analgesics)
 Metoclopramide should only be prescribed for short-term use (up to 5 days)
However, note that this guidance does not apply to unlicensed uses of metoclopramide, e.g. in palliative
care.

dosage: adult up to 60kg - up to 500mcg/kg daily in 3 divided doses given over atleast 3 min
>60kg - 10mg up to 3 times daily given over atleast 3 min
N+V in PC = 10mg 3 times daily, s/c 30-100mg/24 hours

Question 13

Antimuscarinic- Hyoscine hydrobromide

forms, indication, dosage

Answer 13

Available for oral or transdermal administration
Only licensed for motion sickness (has other licensed indications not related to nausea and vomiting).
Can be bought OTC for the management of motion sickness.
Side effects;
 Drowsiness
 Anticholinergic syndrome

Dosage: 150-300mcg 30 mins before strat of journey then 150-300mcg every 6 hours if required, max 900mcg per day

Question 14

5HT3 antagonists e.g. Ondansetron, granisteron, palonosetron

Answer 14

5HT3 antagonists block the 5HT3 receptors in the gastrointestinal tract and in the CNS.
Side effects
 Constipation
 Diarrhoea
 Headache
 Insomnia

Question 15

Ondansetron

forms, indication, dosage

Answer 15

Available for oral, intravenous and rectal administration.
Licensed indications;
 Moderately emetogenic chemotherapy or radiotherapy
 Severely emetogenic chemotherapy
 Prevention of PONV
 Treatment of PONV

Dosage: Initially 8mg 1-2 hours before treatment then 8mg every 12 hours for up to 5 days

Contraindicated in patients with congenital long QT syndrome

Question 16

Granisetron

forms, indication, dosage

Answer 16

Available for oral, intravenous and transdermal administration.
Licensed indications;
 Nausea and vomiting induced by cytotoxic chemotherapy for planned duration of 3- days where
oral antiemetics cannot be used
 Prevention of PONV
 Treatment of PONV
 Management of nausea and vomiting induced by cytotoxic chemotherapy or radiotherapy

Dosage: 1mg dose to be diluted to 5ml given over 30 secs max 3mg per day
transdermal = 3.1mg/24 hours

Cautioned in patients with subacute intestinal obstruction and in patients with susceptibility to QTinterval
prolongation and with concomitant use of drugs that prolong the QT interval

Question 17

Palonosetron

forms, indication, dosage

Answer 17

Available for oral and intravenous administration.
Licensed indications;
 Moderately emetogenic chemotherapy
 Severely emetogenic chemotherapy

Dosage: 500mcg 1 hour before treatment, alternatively 250mcg for 1 dose over 30 secs, 30 min before treatment

Cautioned in patients with a history of constipation or intestinal obstruction and in patients with
susceptibility to QT-interval prolongation and with concomitant use of drugs that prolong the QT
interval.

Question 18

Neurokinin receptor antagonists, e.g. Aprepitant, Fosaprepitant
forms, indication, dosage

Answer 18

Fosaprepitant is a prodrug of aprepitant.
Aprepitant is available only as an oral formulation, fosaprepitant is only available as an intravenous
formulation. Fosaprepitant allows a single iv infusion to be administered on day 1 of a chemotherapy
cycle rather than a 3 day oral regimen which is needed for aprepitant.
Both have the same licensed indication;
 As an adjunct to dexamethasone and a 5HT3 antagonist in preventing nausea and vomiting
associated with moderately and highly emetogenic chemotherapy.

Arepitant Dosage: Initially 125mg taken 1 hour before chemotherapy then 80mg once daily for 2 days

Fosaprepitant Dosage: 150mg administered over 20-30mins and given 30mins before chemotherapy on day 1 of cycle only

Side effects;
 Anorexia
 Constipation
 Diarrhoea
 Dizziness
 Dyspepsia
 Headache

It should be noted that both of these drugs reduce the effectiveness of hormonal contraceptives and
that patients should be advised to use effective non hormonal methods of contraception during
treatment and for two months after treatment ceases.

Question 19

Pregnancy associated nausea and vomiting

Answer 19

Approximately 70% of women will be affected by nausea and vomiting during the first trimester of
pregnancy, symptoms usually start 4 weeks after the last menses and end at 12 weeks. It should be
noted that this is differentfrom hyperemesis gravidarum which is a condition of intractable vomiting;
this can affect between 1 and 5% of pregnancies and may result in serious fluid and electrolyte
disturbances.
In women experiencing morning sickness rather than hyperemesis gravidarum the following non
pharmacological advice may be helpful;
 Try and get lots of rest as tiredness can make symptoms worse
 If sickness is experienced first thing in the morning try and get up slowly and eat a dry piece of
toast or plain biscuit before getting up
 Drink plenty of fluids and sip them little and often rather than a large volume quickly
 Eat frequent small carbohydrate rich meals
 Eat cold meals rather than hot ones so that the smell of food cooking does not induce nausea
 Avoid food or smells that make them feel nauseous
 Wear comfortable clothes without tight waistbands
Ginger is sometimes recommended to treat morning sickness,there is limited scientificevidence to
support its use but it may be beneficial to try taking it, this could be in the form of ginger biscuits or
ginger ale.
Some people recommend acupressure bands, these are stretchy bands worn around the wrist. Again
there is little scientific evidence to support their use as an effective treatment for morning sickness but
as they do not cause any adverse effects on the pregnancy some patients may benefit from trying them.

Question 20

Drug induced nausea and vomiting

Answer 20

Patients can be advised that if they experience nausea after taking a medication it may be beneficial to
take the medication after food (however you must check if there are any specific administration
requirements for the medication- e.g. some antibiotics must be taken on an empty stomach).

Question 21

Motion sickness

Answer 21

Mild symptoms may be improved using the following techniques;
 Keep still- where possible choose to sit in the middle of a boat or plane and use a pillow or
headrest to help keep your head as still as possible.
 Look at a stable object- e.g. the horizon, closing eyes may help relieve symptoms. Patients
should be advised that reading or playing games may make symptoms worse.
 Fresh air-Open windowsto avoid getting too hot and to get fresh air.
 Relax- listen to music as a distraction
 Stay calm- keep calm about the journey, motion sickness is more likely if a patient is worried.
Patients should also be advised to avoid eating a large meal or drinking alcohol before travelling and to remain well hydrated during the journey.
Ginger is sometimes recommended to treat motion sickness however there is limited scientific evidence
to support its use.
Some people recommend acupressure bands, these are stretchy bands worn around the wrist. Again
there is little scientific evidence to support their use as an effective treatment for motion sickness but as they do not cause any adverse effects some patients may benefit from trying them.