Patients must be warned not to swallow betamethasone soluble tablets

The use of betamethasone 500 microgram soluble tablets as a mouthwash is referenced in national guidance sources as a treatment for oral ulceration, including aphthous ulcers​[1,2]​. However, the topical use of this medication is unlicensed.

The summary of product characteristics for betamethasone 500 microgram soluble tablets advises that“betnesol tablets/betamethasone tablets are best taken dissolved in water, but they can be swallowed whole without difficulty”​[3]​. The advice in the patient information leaflet (PIL) states: “Your tablets can be swallowed whole, but they are best taken as a drink after allowing them to dissolve in a glass of water.” The PIL also advises to “always take this medicine exactly as your doctor or pharmacist has told you”​[4]​.

The National Patient Safety team at NHS England and NHS Improvement has received several incident reports related to betamethasone soluble tablets prescribed as a mouthwash, but mistakenly taken orally. One report described hospital admission for adrenal crisis — a potentially life-threatening condition, particularly if not recognised early​[5]​.

To reduce the risk of inappropriate use, dental and medical practitioners prescribing betamethasone 500 microgram soluble tablets for use as a mouthwash need to include detailed instructions on the prescription and also provide information to the patient. The authors would recommend that prescriptions are endorsed with full dose instructions; for example “500 micrograms 4 times a day, to be dissolved in 10–20 mL water and rinsed around the mouth” but include “for use as a mouthwash” and “do not swallow”​[1,5]​.  Pharmacists should ensure that directions on the prescription are replicated on the dispensing label, as well as that the patient/carer is fully aware that betamethasone soluble tablets are intended for use as a mouthwash.

The British and Irish Society for Oral Medicine (BISOM) has a detailed and comprehensive PIL on the use of betamethasone mouthwash, which can be accessed and downloaded from the society website​[6]​. The authors advise that the patient receives the BISOM PIL in addition to the manufacturer’s PIL supplied with the medicine.

Anne Field, professor of oral medicine, Liverpool University Dental Hospital and Christine Randall, senior pharmacist, North West Medicines Information Centre, Liverpool