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Never ever again!


Never ever again!

Mohammed Hussain says he is still haunted by cases of preventable deaths caused by methotrexate poisoning …

‘Never events’ in the NHS are defined as serious incidents that are wholly preventable. The NHS has maintained a list of such events, with the latest iteration from February 2020 listing 15 events.

Of the ‘never events’ listed, five are medicines-related. They include:

·       Mis-selection of a strong potassium solution
·       Administration of medication by the wrong route
·       Overdose of insulin due to abbreviations or incorrect device
·       Overdose of methotrexate for non-cancer treatment
·       Mis-selection of high strength midazolam during conscious sedation.

Of these events, the ones that have caused me greatest concern, particularly in primary care and community pharmacy, have been methotrexate and insulin errors. In a previous role I worked for the NHS and the General Pharmaceutical Council in investigating serious incidents, and in the most serious cases, addressing them at fitness to practise hearings.

I am still haunted by the cases of wholly preventable deaths caused by methotrexate poisoning and having to deal with the consequences for the registrants involved. To this day supplying methotrexate puts my pharmacist senses on full alert, checking, confirming and ensuring that the medication is being prescribed, dispensed and used safely.

I have a daughter with juvenile rheumatoid arthritis and she uses methotrexate to manage her condition, so it is medicine that I have come to know both professionally and personally. It is a wonderful treatment, but its narrow therapeutic window also makes it a potentially dangerous one.

Since 2006 there has been national safety guidance to try and systematically design out these errors. Significant structural safeguards as well as training and awareness have reduced the number of errors, but sadly not to zero. Last month I attended a PCN meeting where the pharmacy team was giving an update on safety issues.

They highlighted that there had been two medicine-related deaths in the region. One was a methotrexate error involving 10mg tablets; the second was a lithium overdose due to failures with monitoring. Both were complex cases in vulnerable patients involving transfers across care settings.
That is not to explain away the cases but to provide some context, in that there are often multiple conflating factors that can transform a near miss into an incident where there is serious patient harm.

Nonetheless I found it shocking that a generation on from a national effort to design out methotrexate harms, patients were still dying from a preventable error.

The most likely errors with methotrexate are either the patient dosing daily instead of once weekly, or the 10mg strength being supplied instead of 2.5mg leading to an overdose. Until last year the BNF stated that methotrexate should only be prescribed in a single strength of tablet - usually 2.5 mg - to reduce the risk of harm from errors.

The BNF has since been updated to advise that the patient's overall polypharmacy burden should be considered when deciding which formulation to prescribe, especially in those with a high pill burden.

In 2020, colleagues at Open Prescribing conducted a study to look at methotrexate 10mg prescribing as a proportion of all methotrexate prescribing. They found that the prescribing of 10mg tablets had fallen across the country, but there were variations with some areas still reporting relatively higher prescribing, the hotspots being Leeds and London.

In addition, they discovered that the higher prescribing practices were also outliers on other quality measures, likely highlighting safety and learning cultures more than individual patient preferences or reviews on pill burden.

Pill burden is a real concern and should be considered, but so is the harm from methotrexate. In my opinion, if prescribers are still intending to use, or even revert to, 10mg tablets, they should make a clear note that they have conducted a pill burden adherence review to transparently explain this use. This can be marked in the patient’s record and also as ‘Additional Information’ using the electronic prescription service.

In this way community pharmacists can address any cases where there is no such clarity. Methotrexate harm is still a ‘Never Event’ and we should continue to do all we can to prevent it. Each death is a personal tragedy for the families and a stain on the consciousness of the NHS.

Mohammed Hussain is an independent contractor and non-executive director of Bradford Teaching Hospitals Foundation Trust.

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