A drug for treating acute episodes of psychosis or mania that should be reserved for specialist use only is being prescribed by GPs in the community, “concerning” NHS data suggest.
The figures — shared exclusively with The Pharmaceutical Journal — show that 14 clinical commissioning groups (CCGs) in England have recorded episodes of primary care prescribing of zuclopenthixol acetate in the past six months.
Figures from the OpenPrescribing database show that 87 zuclopenthixol acetate items were prescribed and dispensed in primary care between June 2020 and May 2021, an increase from 57 items between June 2019 and May 2020.
Zuclopenthixol acetate is indicated for short-term management of acute psychosis, mania or an exacerbation of long-term psychosis, and has a duration of action for two to three days after injection.
However, it is often confused by prescribers with zuclopenthixol decanoate, which is indicated for maintenance treatment in schizophrenia and paranoid psychoses, and is administered regularly at intervals of between one and four weeks.
The British National Formulary (BNF) highlights how the medicines have previously been confused and that care must be taken to ensure the correct drug is prescribed and dispensed. Its safety information says: “Zuclopenthixol acetate is usually used in hospital for an acute episode [of psychosis] and should not be confused with depot preparations which are usually used in the community or clinics for maintenance treatment.”
The prescribing data were a result of analyses carried out by pharmacist Brian MacKenna, alongside colleagues at the DataLab in the Nuffield Department of Primary Care Health Sciences at the University of Oxford. They also created a measure of zuclopenthixol acetate prescribing to alert NHS organisations when potentially inappropriate prescribing may have occurred and enable individual practices to be identified.
In a letter to The Pharmaceutical Journal published on 6 August 2021, MacKenna and his colleagues said: “While the vast majority of CCGs have no primary care prescribing of zuclopenthixol acetate in the past six months, 14 CCGs do.
“Anyone can check these pages to see if their practice, [primary care network], CCG, [sustainability and transformation partnership] or region has recently prescribed zuclopenthixol acetate,” they added.
Ciara Ni Dhubhlaing, president of the College of Mental Health Pharmacy, said she was “concerned” to hear about the number of incidents identified.
“It is known to be a higher potential risk in primary care and for community pharmacists dispensing, neither of whom are likely to be intimately familiar with zuclopenthixol — particularly as it is infrequently prescribed now,” she said.
“I know years ago primary care pharmacists were often involved in checking GP prescribing systems to see if the risk could be reduced by removing acetate altogether, or making it difficult to find on the system, or adding a warning when selected.
“However it may have dropped off the radar more recently and I am concerned to hear about the number of incidents identified.”
Dhubhlaing added that there were a few “break points” that could prevent the error reaching a patient, such as the prescriber identifying the wrong drug selected and amending the prescription; a pharmacist identifying the wrong drug prescribed and contacting the GP to amend the prescription and order the correct formulation; or the administering nurse, or patient themselves, identifying the wrong drug dispensed.
Although, she added that the “lack of familiarity” with an infrequently prescribed drug could “hamper” the effectiveness of all of these break points.
Another letter, published in The Pharmaceutical Journal on 13 July 2021, highlighted the case of an individual who had been prescribed zuclopenthixol acetate, within primary care, on a regular basis over a period of six months.
The authors of the letter said that the similarity of appearance of the two products was “also a concern” and that they “encourage” the manufacturer to review the design of the two boxes and font size of the warning that the acetate formulation was for initial treatment only.