Why ageing changes the picture

Several changes happen together, and they all push in the same direction.

  • Liver metabolism slows. The enzymes that break down medicines become less efficient and liver blood flow decreases, so drugs are cleared more slowly.
  • Kidney function declines. Gradual and normal with age, but it means drugs and metabolites are excreted more slowly.
  • Body composition changes. Proportionally more fat and less water alters how drugs distribute and how long they persist.
  • The brain becomes more sensitive. Independent of how much drug is present, the same concentration often produces a greater effect.
  • Balance systems become less robust. Less reserve to compensate for a medicine that affects steadiness.
  • More medicines are usually involved. Each addition multiplies interactions and stacks similar effects.

The combined result is that a dose which is unremarkable at 40 can be substantially more sedating at 75. This is a well-recognised pattern in geriatric medicine and is not a sign that anything unusual is happening.

What the Beers Criteria actually says

The Beers Criteria is a periodically updated consensus list published by the American Geriatrics Society identifying medicines that frequently cause more harm than benefit in older adults. First-generation antihistamines appear on it, principally because of anticholinergic effects, sedation, confusion and fall risk.

What inclusion means

It means a prescriber should consider whether an alternative exists, and if the medicine remains the right choice, should monitor more closely and use it for the shortest appropriate period.

What inclusion does not mean

It does not mean the medicine is banned. It does not mean anyone should stop taking it. And it does not mean a prescriber who prescribed it made a mistake — there are situations where a Beers-listed medicine is genuinely the best available option for a particular person.

The Beers Criteria is a conversation-starter written for clinicians, not a verdict. Using it as an argument for stopping a medicine unilaterally would be a misuse of it.

Falls

This is the risk with the most serious consequences, and it deserves to be treated as more than a footnote.

The National Institute on Aging identifies medicines that cause dizziness, sedation or blood pressure changes as contributors to falls, and describes falls as a leading cause of injury in older adults. A fall can lead to a hip fracture, a hospital admission, a loss of confidence, reduced activity, and a permanent loss of independence. The chain from a moment of unsteadiness to a changed life is short.

When the risk is highest

Getting up at night ranks first — sedated, in the dark, often in a hurry. Getting up quickly from a chair or bed comes second. New medicines and recent dose changes matter, as does taking several sedating medicines together.

Practical measures

  • A night light along the route to the bathroom
  • Standing up in stages: sit up, pause, then stand
  • Clear pathways, no loose rugs or trailing cables
  • Handrails used on stairs, every time
  • Supportive indoor footwear rather than loose slippers
  • Reporting every fall, including ones where nothing was hurt

That last point matters more than people expect. An unreported near-miss is a warning that never reached anyone who could act on it.

Confusion and the dementia misattribution

Anticholinergic medicines can cause confusion, and in older adults this can be pronounced.

The serious problem is misattribution. New confusion in an older adult is often assumed to be dementia beginning, or simply ageing. If the actual cause is a medicine, that assumption means a reversible problem gets treated as an irreversible one — and sometimes leads to major decisions about living arrangements being made on a false premise.

Any new or worsening confusion in an older adult warrants medical assessment. It can be caused by a medicine, by an infection such as a urinary tract infection, by dehydration, by an electrolyte disturbance, or by a stroke. Several of these are urgent and most are treatable.

Family members are often the first to notice. If someone seems more muddled since a medicine changed, that observation is valuable and should be reported rather than watched.

The over-the-counter blind spot

Because diphenhydramine is available without a prescription, older adults frequently take a sedating antihistamine that no clinician knows about — most often as a sleep aid, which is precisely the pattern the Beers Criteria flags.

Over-the-counter sleep aids, nighttime pain relievers and multi-symptom cold products commonly contain diphenhydramine or doxylamine. Someone taking a prescribed sedating medicine plus a nighttime product is taking two, and neither the pharmacy record nor the prescriber may reflect it.

Everything bought over the counter belongs on the medicine list, and the list belongs in front of a pharmacist.

Asking for a medication review

This is the single most useful action available, and most people do not know they can simply ask for it.

A medication review is an appointment, often with a pharmacist, where every prescription, over-the-counter product and supplement is examined together. It looks for interactions, duplications, medicines that are no longer needed, and practical problems such as difficulty opening containers or reading labels.

Bring the actual bottles — all of them, including anything from a supermarket shelf. Working from memory misses things reliably.

Useful questions: is everything here still necessary, is anything duplicating something else, is anything on the Beers list, could anything be contributing to drowsiness or unsteadiness, and could any of it be simplified.

A review can be requested at any time. It does not require a problem to have occurred first.