Patient safety spotlight: risks of cyclizine misuse and promoting safe provision for patients

April 2024

In this article, we look at the antihistamine cyclizine and its potential misuse, following a Prevention of Future Death report.

According to the NHS website, the antihistamine cyclizine can be used to treat and prevent nausea, vomiting and dizziness following an operation, due to motion sickness or vertigo, or as a side-effect of opioids. The British National Formulary states that cyclizine is available as an oral 50mg tablet 'P medicine' which can be sold from a registered pharmacy premises or supplied as a prescription only medicine (POM) 50mg/ml solution for injection. 

We continuously monitor and respond to reports and queries from coroners and the Prevention of Future Death reports. In a recent report, a patient whose medical history included an eating disorder, cyclizine misuse and factitious disorder, was able to purchase cyclizine from a pharmacy. Sadly, they passed away from cyclizine toxicity.  In the inquest following the patient’s death, the coroner raised concerns that:

“Many professionals who gave evidence had not worked with a patient with such an addiction previously. It was clear throughout the hearing that the knowledge of cyclizine varied amongst many professionals as to how it was prescribed and obtained.”

The report raised that cyclizine is not part of routine toxicology testing and the prevalence of misuse is not well understood.

See the report in full on the Courts and Tribunals Judiciary website

Potential for misuse  

There are known reports of cyclizine misuse due to its sedative and euphoric nature. Cyclizine is a central nervous system (CNS) depressant and so the effects of this are enhanced when it is taken alongside other medicines and substances that are also CNS depressants. 

Examples include alcohol, benzodiazepines, and opioids such as methadone. Furthermore, some people that use methadone recreationally, may combine it with cyclizine to enhance the psychoactive effect.  This is mainly due to the anti-cholinergic effects which may induce hallucinations.  

The World Health Organisation (WHO) describes psychoactive drugs as ‘substances that, when taken in or administered into one's system, affect mental processes, e.g. perception, consciousness, cognition or mood and emotions.’ 

In 2021, a study published in the British Journal of Clinical Pharmacology highlighted the growing concerns relating to the misuse of sedating antihistamines such as cyclizine. The study analysed cases reported to the National Programme on Substance Abuse Deaths from England occurring in 2000–2019.

One of the conclusions from the study was that the ‘rising trend in sedating antihistamine-related deaths may be contributed to by their increasing availability and the perceived negligible dangers associated with antihistamines, both from the general public and learned professionals.

“When working in specialist substance misuse services, I found it was rare for people to access treatment with cyclizine as their primary substance. When people were misusing it, it was more likely to be alongside other substances or other medicines, such as heroin or methadone. Individuals who misuse over the counter medicines have told me that their pharmacy could have done more to have a positive impact on their recovery journeys. For example, by asking about how they planned to use the medicines and providing harm reduction advice in a non-judgemental way. In these situations, helping people to access specialist services is also of paramount importance, so that they can access the support they need in a timely way” 

Roz Gittins, Chief Pharmacy Officer, GPhC

Aligning GPhC principles and standards to supplying cyclizine safely to patients 

Infographic about cyclizine

Risk assessment and management 

Our standards for registered pharmacies require pharmacy professionals and owners to identify the risks associated with providing a pharmacy service. Given the potential for misuse of cyclizine, pharmacy professionals and owners should consider within their risk assessments how they will ensure that cyclizine and other medicines that are liable to misuse will be supplied safely, and in the person’s best interest. Our standards also require that children and vulnerable adults are safeguarded.  

Areas to consider within a risk assessment include, but are not limited to: 

  • Staff are suitably trained to appropriately gather all the relevant information they need to make an informed decision on whether a supply of cyclizine would be safe and appropriate. 
  • Staff have appropriate training to identify signs of misuse. Find out more about common behaviours associated with cyclizine misuse in this study on cyclizine dependence, which was referenced in the Prevention of Future Deaths report.
  • Staff are aware of when and how to signpost or escalate concerns. 
  • Pharmacy teams can record when inappropriate requests are made and share learning and reflections among their team members. Where appropriate, learnings should be shared with other healthcare professionals involved in the person’s care such as their GP.  

Provision of medicines can also occur from a distance-selling or online pharmacy. Providing pharmacy services at a distance, especially online carries particular risk. Our guidance for registered pharmacies providing services at a distance including on the internet provides support for appropriate provision of medicines, medical devices and pharmaceutical care, which keeps to the law and meets our standards. 

See the guidance

Risks to consider when providing cyclizine at distance include, but are not limited to: 

  • considering whether cyclizine is appropriate to provide at a distance, including on the internet
  • being able to verify the person’s identity to ensure that they are who they claim to be
  • ensuring all relevant information about the person requesting the medicine is received and verified prior to making a supply and that where appropriate, this includes gaining consent to access relevant medical records or communicating with the person’s GP or others involved in their care
  • identifying requests for cyclizine that are inappropriate, for example, by being able to identify multiple orders to the same address

Patient education and counselling 

As with all counselling or interventions that take place, pharmacy professionals should ensure that patient confidentiality, privacy and dignity are maintained. Pharmacy teams should:  

  •  question and counsel patients appropriately when cyclizine is requested or supplied
  • make sure information provided to patients and or their representatives is clear, easy to understand and tailored to them, and that patients have the opportunity to ask further questions about their medicines
  • advise about potential side effects, including potential sedation, drowsiness and dizziness, and advise not to drive or operate machinery if these occur
  • advise about potential interactions with other medicines or substances, and especially those which may cause central nervous system depression, such as alcohol, benzodiazepines, and opioids such as methadone 
  • encourage them to consult their pharmacist or other healthcare professional before taking any additional medication

Pharmacy professionals and owners should ensure that they have adequate training for themselves and their teams to be able to safely manage requests for cyclizine. 

In line with our standards for registered pharmacies, all team members must raise concerns when they feel that requests for cyclizine are inappropriate. Staff should have ‘the appropriate skills, qualifications and competence for their role’ and all members of the pharmacy team should be aware that cyclizine is a medication that may be misused. 

When individuals request cyclizine on a frequent basis, or problematic use is known or suspected, patients should be referred to a pharmacist for suitable intervention,

This may include but is not limited to:

  • refusing to supply cyclizine and offering alternative treatment choices
  • reporting dependency via the MHRA yellow card scheme
  • appropriate signposting to their GP or other healthcare professionals
  • referral to other support organisations such as specialist substance misuse treatment services. Find out more about further support available via the NHS website

Our inspectors routinely highlight examples of good practice identified through inspection and these are published on our knowledge hub. Although to date these examples relate mainly to the supply of codeine-based medicines, the learning points are also relevant to other medicines which may be subject to misuse, such as cyclizine.

Examples of notable practice from our knowledge hub include:  

Previous examples of good practice which have been identified in respect of the sale and supply of high-risk medicines include:

  • producing new standard operating procedures to identify and manage risks

  • individual learning modules for pharmacy team members covering high-risk medicines

  • written checklists to ensure consistent patient questioning, which are regularly audited

Find out more

Below is a list of resources to help you make sure you are meeting our regulatory standards and guidance and working in line with good practice. 

GPhC resources

  • Our standards for registered pharmacies set out the requirements for the provision of pharmacy services at or from a registered pharmacy 
  • Our guidance for registered pharmacies providing pharmacy services at a distance, including on the internet, explains what pharmacy owners should consider before deciding whether any parts of their pharmacy service can be provided safely and effectively at a distance (including on the internet) 
    See the guidance on providing services at a distance
  • Our GPhC guidance on managing concerns about online sale and supply of habit-forming medicines discusses some of the types of concerns and poor practices that have been identified in this area, an the roles of pharmacy professionals who may be involved in this process. 
    See the guidance on managing concerns

Additional resources

You will need a login to access the following educational resources:

Published on
Last updated on