Neurological
Medicines for Delirium
A sudden change in mental state — confusion, disorientation and altered awareness — usually triggered by illness, especially in older or frail people, and often reversible.
Education and reference only. This explains which medicines are used and why, in plain language — it deliberately contains no doses and is not a substitute for advice from your doctor or pharmacist. Always discuss your own treatment with a qualified clinician, and check the BNF and the product labelling for prescribing detail.
Quick answer
What is Delirium?
Delirium is a sudden and often fluctuating change in a person's mental state, causing confusion, difficulty concentrating, disorientation, and altered awareness that develops over hours to days. It is different from dementia (which develops gradually), though people with dementia are more prone to it.
- How it is treated: The key is to find and treat the underlying cause — such as an infection, dehydration, constipation, pain, or a problem with medicines — which often resolves the delirium, though recovery can take time.
- Self-care: For those at risk (older or frail people), staying hydrated, keeping mobile, ensuring good sleep, using glasses and hearing aids, avoiding unnecessary medicines, and treating infections and constipation promptly help prevent delirium.
- When to seek help: Seek prompt medical assessment if a person (especially older or frail) suddenly becomes confused, disorientated, drowsy or agitated — delirium usually signals an underlying illness that needs treating.
What it is
Delirium is a sudden and often fluctuating change in a person's mental state, causing confusion, difficulty concentrating, disorientation, and altered awareness that develops over hours to days. It is different from dementia (which develops gradually), though people with dementia are more prone to it. There are two main patterns: "hyperactive" delirium, with restlessness, agitation, and sometimes hallucinations, and "hypoactive" delirium, with drowsiness, withdrawal and reduced activity — the quieter form is easily missed. It is very common in unwell older people, particularly in hospital, and is usually triggered by an underlying problem such as an infection (a urine or chest infection is common), dehydration, constipation, pain, certain medicines, low oxygen, or being in an unfamiliar environment. Recognising it matters because it signals that the person is unwell and needs assessment, and it is often reversible when the cause is treated.
How it is treated
The key is to find and treat the underlying cause — such as an infection, dehydration, constipation, pain, or a problem with medicines — which often resolves the delirium, though recovery can take time. Alongside this, supportive care helps: a calm, familiar environment with good lighting, glasses and hearing aids available, reassurance and reorientation, involvement of family, good hydration and nutrition, promoting sleep and mobility, and reviewing medicines. Medication to calm agitation is used only when necessary and with caution. Because delirium can be distressing and is associated with poorer outcomes, and can be the first sign of serious illness, prompt recognition and assessment are important. Prevention — through attention to hydration, mobility, sleep, and avoiding unnecessary catheters and medicines — is emphasised in those at risk. Most people recover, especially when the cause is treated.
For this condition, these medicines
Medicine classes used for Delirium
Each links to a full, dose-free guide — what it is, how it works, who can and cannot use it, side effects, interactions and FAQs.
Beyond medication
Lifestyle and self-care
For those at risk (older or frail people), staying hydrated, keeping mobile, ensuring good sleep, using glasses and hearing aids, avoiding unnecessary medicines, and treating infections and constipation promptly help prevent delirium. Familiar surroundings and people aid recovery.
When to get help
When to see a doctor
Seek prompt medical assessment if a person (especially older or frail) suddenly becomes confused, disorientated, drowsy or agitated — delirium usually signals an underlying illness that needs treating. Seek urgent care if they are very unwell.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
Answers
Delirium: frequently asked questions
What is the difference between delirium and dementia?
Delirium comes on suddenly (over hours to days), often triggered by illness, and fluctuates — and is usually reversible when the cause is treated. Dementia develops gradually over months to years. People with dementia are more prone to delirium.
What causes delirium?
It is usually triggered by an underlying problem — commonly an infection (such as a urine or chest infection), dehydration, constipation, pain, certain medicines, or an unfamiliar environment. Finding and treating the cause is key.
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