Anti-emetic guidance for patients undergoing radiotherapy

Warning
Risk group Very high High Moderate Low Minimal
RT site Total nodal irradiation Craniospinal irradiation

Abdomen

Pelvis (large volume)

Hemi-body - upper

Brain

Head & neck

Thorax

Pelvis (small volume)

Breast 

Extremities

Before first RT Granisetron* 1mg oral Granisetron* 1mg oral Granisetron* 1mg oral Nil
Ongoing for home

Granisetron* 1mg od oral 

Metoclopramide 10mg tds oral

Granisetron* 1mg od oral

Metoclopramide 10mg as required oral

Metoclopramide 10mg tds oral

Granisetron* 1mg as required oral

Nil
Rescue options

Granisetron* 2mg od

Dexamethasone (only after discussion with transplant team)

Prochlorperazine as required or regular (see notes below for dose information)

Granisetron* 2mg od

Metoclopramide 10mg oral regular

Prochlorperazine as required or regular (see notes below for dose information)

Granisetron* 1mg od regular

Prochlorperazine as required or regular (see notes below for dose information)

Metoclopramide 10mg oral as required or regular

Granisetron 1mg oral as required or regular

Prochlorperazine as required or regular (see notes below for dose information)

 

Review

Weekly review of medicines

Stop or reduce as required when possible

Monitor for side effects and prescribe alternatives or add in supportive medications such as laxatives when needed

 

Anti-emetic Oral dose Prescribing notes
Granisetron

1-2mg OD

Can be used BD if OD dosing is ineffective

May reduce lower bowel motility, patients with signs of sub-acute intestinal obstruction should be monitored following administration. As for other 5-HT3 antagonists, ECG changes including QT interval prolongation have been reported. Therefore, caution should be exercised in patients with cardiac rhythm or conduction disturbances, in patients using other medications that prolong QT interval (see Table 7), in patients treated with anti-arrhythmic agents or beta-adrenergic blocking agents and in patients with significant electrolyte disturbances (low potassium, magnesium or calcium). Concomitant use of cardio-toxic drugs (e.g. anthracyclines) may increase risk of arrhythmias.

Common side effects: headache and constipation - consider laxatives, caution in patients with history of migraines

*Ondansetron

4mg BD (usual dose)

Dose range 4-8mg up to TDS

Administer with caution to patients who have or may develop prolongation of QTc.(see above for information beside granisetron). Ondansetron is known to increase large bowel transit time; patients with signs of sub-acute intestinal obstruction should be monitored following administration.

Interactions: Potent inducers of CYP3A4 such as phenytoin, carbamazepine, and rifampicin, may increase the oral clearance of ondansetron and decrease ondansetron blood concentrations.  Data from small studies indicate that ondansetron may reduce the analgesic effect of tramadol.

*Melts formulation available for patients unable to swallow tablets – useful alternative 5HT3 antagonist for this situation.
Metoclopramide

10mg TDS or 6 hourly as required,

Max of 3 doses in 24 hrs (oral liquid available)

The EMEA issued advice on use of metoclopramide in 2013 (ECC metoclopramide statement) restricting the dose and duration of use of the medicine to minimise the known risks of potentially serious neurological SE’s.

Metoclopramide is associated with agitation and extra-pyramidal symptoms particularly in young females, in addition prolonged use may lead to neurological side effects in elderly patients in particular. Caution is advised in patients with Parkinson’s Disease and taking concurrent neuroleptics.

Bowel transit time can be reduced and it is contra-indicated in GI obstruction.

Max daily dose 10mg TDS, max duration of regular treatment 5 days, after which it can be taken as required. Regular use for longer than 5 days can be considered in patients who remain poorly controlled and are without risk factors at the prescriber’s discretion
Prochlorperazine 5-10mg 2-3 times daily or Buccastem 3-6mg BD

May cause drowsiness.

Avoid in liver or renal dysfunction, Parkinson’s disease, cardiac failure and hypothyroidism.

Buccal preparation (Buccastem®) useful for the vomiting patient as absorbed from the oral mucosa.

Place tablet between upper lip and gum and leave to dissolve.
Dexamethasone 2-8mg

May induce / unmask/ destabilise diabetes – advise patients of symptoms of thirst / increased diuresis, increase BM monitoring in patients with diabetes as per ECC guidelines.

May cause dyspepsia when used at high dose for prolonged course - consider PPI prophylaxis as per ECC policy.

Editorial Information

Last reviewed: 05/01/2024

Next review date: 05/01/2027

Author(s): Edinburgh Cancer Centre.

Version: 01.0

Approved By: Authorised by CTAC. Refer to Q-Pulse for approval details

Reviewer name(s): Stewart J.