Medicine side effects or dementia? What families should know

This is one of the hardest questions a family can sit with. Your parent seems different, less sharp, more forgetful or more confused than they were a few months ago, and the word that comes to mind is frightening. Before that word settles in, it’s worth knowing something factual: certain medicines commonly prescribed to older people can produce symptoms that overlap with what many people associate with dementia — and working out which is which is exactly the kind of question a full medicine list, laid out clearly for a doctor, is built to help answer.

Why this is so hard to tell from home

Confusion, slower thinking, forgetting recent conversations, and disorientation can all show up whether the cause is a medicine, an infection, dehydration, a change in routine, or a change in the brain itself. From the outside, at the kitchen table, these can look identical. That’s not a failure of observation on your part — it’s the reason this needs a clinical assessment rather than a guess, however careful the guess.

Which medicines can cause confusion-like symptoms?

A number of medicine types used regularly by older people are recognised as being able to affect thinking, alertness and memory-like function, particularly as more of them are combined. These include sedatives and sleeping tablets, strong pain relief (opioids), and some medicines for bladder problems, allergies or sleep that carry what pharmacists call anticholinergic effects.¹

Anticholinergic is simply the term for a group of medicines that block a particular chemical messenger in the body. In older people, that blocking effect can show up as forgetfulness, confusion, dry mouth, constipation or unsteadiness — often several of these together, and often described by families in almost the same words used for early dementia.¹ More broadly, medicines are a recognised trigger for delirium, a sudden change in thinking or behaviour, alongside things like acute illness, surgery or injury.²

Medicines aren’t the only thing a GP will consider

A change in thinking or memory can have several possible explanations, and medicines are only one of them. Infections, dehydration, poor sleep, pain that isn’t being managed well, and changes in routine or environment can all affect an older person’s thinking in ways that look similar from the outside. This is exactly why the question needs a doctor working through it properly, rather than a family reaching a conclusion on their own — and it’s also why simply stopping or changing a medicine without medical advice is never the right first step, even if a medicine turns out to be part of the picture.

What a doctor actually needs to tell the difference

Timing matters more than almost anything else. Did the change in your parent start or get noticeably worse around the same time as a new medicine, a dose increase, or a combination of medicines started close together? That single detail, told clearly, is often more useful to a GP than a general description of “more confused lately.”

A doctor also needs the complete list — not just the medicines your parent takes regularly, but anything over-the-counter, any vitamins or herbal products, and anything started or stopped recently by a different prescriber. It’s common for one part of this list to be missing simply because no single appointment ever asked for all of it at once.

Where a medication review fits in

A Home Medicines Review doesn’t diagnose anything, and it isn’t a substitute for your parent’s doctor. What it does is give the GP an organised, complete picture: every medicine your parent is actually taking, how and when, alongside what you and your parent have noticed and roughly when it started. That structured picture is exactly the input a GP needs to work out whether a medicine is contributing, and what — if anything — should change, on their own clinical judgement.

The review is arranged through your parent’s GP, and it’s funded by the Australian Government’s Community Pharmacy Programs, so there’s no cost to your family. If several medicines have built up over time, or came from more than one prescriber, that alone is often reason enough for a GP to consider a referral — you can read more about that pattern in our article on signs your parent may be on too many medicines.

What to do while you wait for answers

Book an appointment with your parent’s regular GP and go along if your parent is comfortable with that. Bring every medicine your parent takes, in its original packaging if you can, along with a simple note of what you’ve noticed and roughly when it started. Ask directly whether a medication review might help build a clearer picture. None of this requires you to know the answer yourself — your job is to notice and describe clearly; working out the cause is what your parent’s GP, supported by a structured review where needed, is there to do. For the practical steps of arranging one, see our guide to organising a medication review for your parent.

It’s worth saying plainly what this article isn’t: it isn’t a way to self-diagnose your parent, and it isn’t a reason to change or stop anything before speaking with their doctor. What it is meant to do is give you the vocabulary to describe what you’ve noticed clearly, and the confidence to ask your parent’s GP a direct question: could any of this be coming from a medicine, and is it worth a proper look at everything they’re taking?

References

1. healthdirect, Medicines safety for older people: healthdirect.gov.au
2. Australian Commission on Safety and Quality in Health Care, Delirium Clinical Care Standard: safetyandquality.gov.au
3. healthdirect, Home medicines review: healthdirect.gov.au
4. Pharmacy Programs Administrator, Home Medicines Review: ppaonline.com.au