Serious side effects can be caused if betamethasone soluble tablets used as mouthwash are swallowed. Providing clear patient directions can help prevent harm.

Using betamethasone soluble tablets as a mouthwash

Betamethasone 500 microgram soluble tablets prepared as a mouthwash are used to treat recurrent aphthous ulceration (recurrent mouth ulcers). This use is off-label but is a recognised treatment described in the BNF and in a NICE Clinical Knowledge Summary.

The BNF recommends a dose for oral ulceration for adults and children 12 to 17 years of 500 micrograms four times a day. The tablet should be be dissolved in 20 mL water, rinsed around the mouth, and not swallowed.

Patient safety concerns

The National Reporting and Learning System has received a number of incident reports related to betamethasone soluble tablets prescribed as a mouthwash but mistakenly taken orally. One report described hospital admission for adrenal crisis.

Side effects of corticosteroids are well known as listed in the BNF. Many are serious including risk of adrenal crisis which was highlighted in the August 2020 NPSA Alert Steroid Emergency Card to support early recognition and treatment of adrenal crisis in adults.

Risks and their mitigation

Known risks can be managed to reduce the likelihood of patient harm.

Prescribing and dispensing


NHS electronic prescribing and medicines administration (EPMA) and patient medication records (PMRs) use Summaries of Product Characteristics (SPCs) to inform prescribing and dispensing fields. When medicines are used off-label relevant formulation and administration information does not automatically appear when a prescription is generated or dispensed. Consequently ‘betamethasone 500 microgram soluble tablets for use as a mouthwash’ may not appear as a prepopulated option when generating a prescription or producing a dispensing label.



Off-label medicines in EPMA systems may require active intervention to enable appropriate administration and relevant warnings to be highlighted. e.g. ‘use as a mouthwash’ and ‘do not swallow’. Best practice would be to add ‘do not swallow’ to the prescription directions to ensure inclusion on the dispensing label.


Extra vigilance is needed when a prescription for betamethasone soluble tablets is received to establish the intent of the prescriber.

PMR automations may need to be over-ridden to label with patient instructions for use as a mouthwash and include additional warnings from the prescription such as ‘do not swallow’.

Patient counselling


Patient/carer may be unclear about specific administration recommendations due to poor counselling and have no understanding that dissolved tablets should not be swallowed.


Ensure the patient/carer is fully aware that betamethasone soluble tablets are intended for use as a mouthwash. Advise how to prepare and use the soluble tablets and reinforce the solution should not be swallowed. Ensure pharmacy/nursing staff dispensing/issuing the medicine are trained.

Patient Information Leaflet (PIL)


The PIL included with betamethasone 500 microgram soluble tablets does not mention use as a mouthwash. The manufacturer’s patient information leaflet advises that soluble tablets are dissolved and taken as a drink. If no additional patient information is provided by the prescriber or pharmacist describing use as a mouthwash there is a risk the patient may swallow the solution.


Ensure that the prescriber and/or pharmacist provides the patient with the PIL from the British and Irish Society for Oral Medicine.

Additional information

Guidance provided by the MHRA and General Medical Council on prescribing a medicine outside the terms of its licence states that this should only be necessary when there is there is no suitably licensed medicine that meets the patient’s need.

Update history

  1. Hyperlink to GMC advice on off-label prescribing updated, content reviewed, remains current.
  1. Title and URL shortened. Minor formatting amendment.
  1. Published

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