Medicine-induced delirium and confusion in older adults

MedlinePlus describes delirium as a mental state in which a person is confused, disoriented and unable to think or remember clearly, usually beginning abruptly. Symptoms fluctuate across the day. The person may be drowsy and withdrawn, restless and agitated, or swing between the two. Hallucinations, muddled speech, disturbed sleep and mood swings are common.

Families often say the person is "not themselves". That observation is valuable. A relative who normally manages their own tablets and conversation but is now muddled, sleepy or suspicious should prompt an urgent assessment, whether the change began at home, in hospital or in a care home.

With age the kidneys and liver clear medicines more slowly, body composition changes, and the brain is more sensitive to anything that affects chemical signalling. Many older adults also take several medicines, and each additional one raises the chance of interactions. A dose that was fine years ago may become too much after an illness, dehydration or a fall in kidney function.

Delirium is also rarely caused by one thing. A medicine often tips the balance in someone who already has an infection, pain, constipation, poor sleep, dehydration or early dementia. Looking for the medicine does not mean other causes are ignored.

The list is illustrative rather than complete. Any new medicine, dose change, or stopped medicine in the preceding days is relevant, including over-the-counter and herbal products.

MedlinePlus lists a medical history, physical and neurological examination, mental state testing and laboratory or imaging studies as the usual approach. Clinicians commonly use short bedside tests of attention and orientation, and ask relatives how the person was before. Blood tests look for infection, kidney and liver problems, sodium, sugar and calcium, and a urine test may be done though a positive result alone does not prove a urinary infection.

A structured medication review is central. It asks which medicines were started or increased recently, which could be sedating or anticholinergic, which have been missed or stopped, and whether kidney function affects the dose. Bring every box, bottle and patch, plus any supplements, to the assessment, because accurate lists often change the picture.

The core treatment is to find and treat the cause. MedlinePlus notes that treating the cause often leads to full recovery. When a medicine is implicated, the prescriber may stop it, reduce it, swap it or review the need for it, sometimes in stages to avoid withdrawal. Supportive care matters alongside this.

Helpful measures include a quiet, well-lit room, a clock and calendar, hearing aids and glasses within reach, regular fluids and food, daytime activity and good night-time sleep, and consistent familiar people. Family presence is calming. Medicines to calm severe agitation are generally a last resort and used cautiously because many of them can worsen delirium in older people.

Recovery can take days to weeks, and some people have a longer period of slowed thinking afterwards. Delirium can also unmask or accompany dementia, so a memory assessment is sometimes arranged once the person has recovered.

A regular review of the whole medicine list, ideally with a pharmacist or GP, is the most practical safeguard. The aim is to stop what is no longer needed, avoid combining several sedating or anticholinergic medicines and use the lowest effective dose of what remains.

• Ask for a structured medicines review after any hospital stay.

• Keep an up-to-date list, including supplements, to hand for every appointment.

• Do not stop long-standing sleeping tablets, painkillers or other medicines abruptly.

• Prevent dehydration and constipation, which both worsen confusion.

• In hospital, ask staff to minimise sedatives and to keep the person's glasses, hearing aids and routine.

The NHS advises going to A&E or calling 999 if someone suddenly becomes confused, because causes can be life-threatening, and not to drive them yourself. While waiting, stay with them, speak calmly in simple language, reassure them, avoid asking many questions and avoid restraining them unless there is a safety risk. Have the medicines list ready for the ambulance crew.