Clinical Clanger: ‘Can I have some more prochlorperazine for my dizziness?’

Continuing our series of clinical scenarios that can be mishandled in primary care, surgeon and otolaryngology specialist Mr Gerard Kelly advises how to avoid overtreatment of dizziness.

Scenario
A 56-year-old female call centre worker presents to your surgery. Her medical history is unremarkable and she takes no medication. Six weeks ago she returned home from a restaurant and felt something was ‘not right’ with her balance. She turned over in bed and the room started to spin. The next morning she had significant rotational vertigo and nausea. She attended A&E, where she was prescribed prochlorperazine for her initial symptoms. 

The symptoms lasted two days, during which time she rested at home and was able to mobilise with self-care. She had no other otological symptoms – no hearing loss, ear fullness or tinnitus – and no other neurological symptoms. 

Her symptoms improved slowly, but for the last few days she has again felt off balance and dizzy, especially when she turns her head quickly, although she has no rotational vertigo. She has already obtained a repeat prescription for prochlorperazine via the practice (5mg TID) and has been taking this since the incident. She is keen to continue her medication as it was very effective for the initial incidence.

Examination is normal, she has no nystagmus and normal cranial nerve function. Clinical testing of hearing and tuning-fork testing is normal. 

The reality
This patient’s initial presentation is relatively common. She probably had an acute vestibular syndrome (an acute disorder of the inner-ear balance mechanism). If seen acutely, such a patient would have nystagmus, but this tends to settle quickly and can often not be elicited by the time the patient is seen in general practice. 

One of BNF-listed indications for prochlorperazine is labyrinthine disorders. For these, it is a useful treatment in the short term but the BNF also lists one of the ‘common or very common side-effects’ as dizziness! So prochlorperazine can help with severe symptoms but can become the problem and not the solution. Because it can be very helpful for an initial attack of vertigo, patients continue its use if dizziness continues, thinking that it will eventually cure the condition. It is also anxiolytic, so patients may request a repeat prescription, as dizziness is an anxiety-provoking disorder. 

When the condition is likely to be peripheral (vestibular, not central), in patients aged over 50 and with risk factors for a cerebrovascular accident, vestibular sedatives such as prochlorperazine can be prescribed but the patient should always be reviewed. In patients under 50 with no risk factors, practice safety netting by explaining that they should be reviewed if there is no improvement.

The issue
Prochlorperazine is a first-generation antipsychotic. It blocks dopamine receptors found in the CTZ (chemoreceptor trigger zone), which prevents activation of the vomiting centre.

Prochlorperazine is commonly used correctly to treat dizziness, if used only for a short period – usually just a few days, up to two weeks at the most. It can cause significant extrapyramidal symptoms, including:

• Acute dystonia. 
• Tardive dyskinesia. 
• Parkinsonism.
• Akathisia.
• Neuroleptic malignant syndrome. 

Side-effects from its anticholinergic action include:

• Anorexia
• Blurred vision
• Constipation
• Dry mucosa.
• Urinary retention. 
• Sedation due to its action as an antihistamine. 

If used for a prolonged period, it can result in vestibular suppression so that acute rotatory vertigo does not occur but a sense of imbalance does (dizziness is a common side-effect). Make patients aware that acute balance disorders are self-limiting and while drug treatment in the short term is effective it can hamper recovery. Real improvement comes with adaptation in labyrinthitis and vestibular neuritis; the balance system is plastic – it adapts and does so more effectively without medication. 

Benign paroxysmal positional vertigo (BPPV) should be treated with the Epley manoeuvre –  medication is ineffective due to the severe and very transient nature of the vertigo in BPPV. Vestibular migraine is much more common that previously realised and the reduction in stressors through regular, good-quality meals and sleep is of much greater importance than medication.

The evidence
NICE has guidance on the management of peripheral vertigo, including BPPV, Ménière’s disease, and vestibular neuritis.¹

Avoiding a clanger
In vestibular neuritis, prochlorperazine can be used to settle the initial acute symptoms, but thereafter the patient’s vestibular system must be given a chance to recover. The most important aspect of treatment is vestibular rehabilitation. Recommend the use of Cawthorne Cooksey exercises but explain to the patient that when doing these exercises they will initially feel more off balance and vestibular compensation will occur with time. 

In vertigo management, establishing a diagnosis is key to offering effective, disease-specific treatment. BPPV can be treated effectively with the Epley manoeuvre (and patients can do their own manoeuvre with a well-researched YouTube tutorial). Vestibular migraine is much more common than Ménière’s disease.

Caveats
Prochlorperazine should not be used regularly for a prolonged period, although in an unstable condition such as Ménière’s when attacks can happen repeatedly, the buccal form of the drug (to circumvent the problem with vomiting of oral medication) can help symptoms and repeated use for symptomatic periods only can be very effective.

Mr Gerard Kelly is a consultant ENT and skull base surgeon, Leeds Teaching Hospitals NHS Trust and honorary senior lecturer in otolaryngology, University of Leeds

References

1. NICE Clinical Knowledge Summary: Peripheral Vertigo. December 2022
2. Dommaraju S and Perera E. An approach to vertigo in general practice. Aust Fam Physician 2016;45(4):190-4

To read more articles from Pulse’s clinical clangers series, click here