Polypharmacy in the elderly: risks, data and practical solutions

Carmen is 82 years old and every morning she faces the same table: nine boxes of medication, three different schedules, two pills that must be taken on an empty stomach, one that cannot be combined with calcium, and another that was prescribed six months ago and she no longer remembers why. Her daughter has taped a colour-coded chart to the fridge door. Some days it works. Others, it doesn't.

What is striking about this situation is not its complexity. It is how common it is. In Spain, more than a third of people over 65 take five or more medications on a chronic basis. Among those over 85, the figure exceeds 50%. Polypharmacy is not a clinical exception: it is the everyday landscape of ageing.

What polypharmacy is and when it becomes a problem

The term polypharmacy is commonly used to describe the simultaneous use of five or more medications on a chronic basis. But the numerical definition is misleading when taken in isolation. What matters is not how many drugs a person takes, but whether each of them is still necessary, appropriate, and compatible with the rest.

The literature distinguishes between appropriate polypharmacy and problematic polypharmacy. In the former, each medication responds to a clear indication, has been reviewed periodically, and the patient understands why they take it. In the latter, prescriptions accumulate without review, with duplications, potential interactions, or drugs that no longer provide clinical benefit. The problem is not necessarily taking many medications. The problem is taking them without anyone having paused to evaluate the whole picture.

According to the National Health Survey of INE (Spanish National Statistics Institute), 36.4% of people over 65 in Spain take five or more medications. Prevalence grows with age and with the accumulation of chronic conditions: hypertension, diabetes, dyslipidaemia, osteoarthritis, depression. Each diagnosis adds a drug. Each specialist adds a perspective. But rarely does anyone look at the full picture.

The risks that go unseen

As the number of drugs increases, the risk of drug interactions does not grow linearly, but exponentially. With two medications there is one possible interaction. With five, there are ten possible combinations. With nine, like Carmen's, the number rises to thirty-six. Not all are clinically relevant, but many go unnoticed until the patient arrives at the emergency department.

One of the most insidious phenomena is the prescribing cascade. It works like this: a medication produces a side effect that is interpreted as a new symptom, for which another drug is prescribed, which in turn generates its own adverse effects. A classic example: an antihypertensive causes ankle oedema, a diuretic is prescribed, the diuretic causes hypokalaemia, a potassium supplement is added, the potassium irritates the stomach, a gastric protector is prescribed. Four medications have grown from one. The original treatment is still there, but the patient can no longer remember which came first.

The clinical data are compelling. People who take five or more medications have three times the risk of falling — one of the leading causes of hospitalisation and loss of independence in older adults. Drugs with sedative, hypotensive, or anticholinergic effects contribute directly to instability. Furthermore, accumulated evidence links polypharmacy with cognitive impairment, especially when drugs with a high anticholinergic burden are combined.

According to data from SEGG (Spanish Society of Geriatrics and Gerontology), approximately 30% of hospitalisations in older people are related to medication-related problems: adverse reactions, interactions, dosing errors, or non-adherence caused by the very complexity of the therapeutic regimen. These are not patients who have stopped taking their medicines. They are patients who take them all, but incorrectly.

The problem of fragmentation

Polypharmacy does not arise in a vacuum. It is, to a large extent, the product of a fragmented healthcare system. A chronic patient with multiple conditions may be seen simultaneously by their primary care physician, a cardiologist, an endocrinologist, a rheumatologist, and perhaps a psychiatrist. Each prescribes from their specialty, with limited access to the complete pharmacological history, and often without a joint review of the treatment.

The result is that the patient becomes the only point of integration. It is the older person who carries prescriptions from one doctor to another, who remembers — or does not — to mention what the previous specialist prescribed, who decides whether or not to take a tablet when it causes discomfort.

Electronic prescribing has improved the traceability of prescriptions, but it does not resolve the underlying problem. The fact that a drug is prescribed does not mean it is appropriate in combination with the other eight. Coordination between prescribers remains insufficient, and the responsibility of managing complexity falls on those who have the fewest resources to do so.

Solutions that work

The good news is that problematic polypharmacy has a solution. It does not always require sophisticated technology or sweeping structural reforms. Often it is enough to perform a clinical gesture that is rarely practised today: sitting down with the patient and reviewing, drug by drug, whether each one still makes sense.

Medication review is an intervention with robust evidence. It consists of systematically evaluating a patient's complete treatment, identifying duplications, interactions, medications without a clear indication, and opportunities for simplification. In many European countries, community pharmacies already participate in these review services. In Spain, the new community pharmacy model is moving towards a care function that goes beyond dispensing.

Deprescribing is the natural complement to review. It consists of withdrawing, in a planned and supervised manner, those medications that are no longer necessary or whose risk outweighs the benefit. It is not stopping treatment: it is treating better, with less. A process that requires clinical judgement, but also communication with the patient, who often fears stopping a medication they have been taking for years.

Personalised Dosage Systems (PDS) — known in Spain as SPD — represent another effective tool. These involve preparing medication grouped by dose time (morning, midday, evening) in individualised blister packs, so that the patient only needs to open the corresponding compartment. They eliminate the need to interpret boxes, leaflets, and schedules. Community pharmacies prepare and update them whenever the treatment changes.

To these resources are added digital monitoring tools. Platforms that allow the complete medication to be recorded, reminders to be set, potential interactions to be flagged, and direct communication to be maintained between pharmacy, patient, and caregiver. They do not replace clinical review, but they make it easier and more frequent.

The caregiver as a key player

Behind many polypharmacy patients there is a person who does not appear in the clinical record but who holds the system together: the caregiver. Often a daughter, son, or partner who has taken on the task of organising pill boxes, accompanying appointments, interpreting treatment changes, and monitoring side effects.

This burden is enormous and barely recognised. The caregiver has no medical training, no direct access to the patient's records, and frequently has no one to ask when a question arises outside of consultation hours. Managing another person's medication is a cognitive task that generates anxiety, errors, and exhaustion.

Technology can significantly reduce that burden. A digital system that allows the caregiver to see the up-to-date medication, receive dose alerts, and communicate with the pharmacy transforms a solitary task into a shared process. As we analyse in our article on the caregiver's role in medication management, supporting the caregiver is indirectly supporting the patient.

A systemic issue, not just a drug issue

Polypharmacy is, ultimately, a symptom of something broader: a healthcare model designed for acute illness that has not fully adapted to the reality of chronic disease. When a person lives with four or five diagnoses for decades, they need more than prescriptions: they need coordination, periodic review, and continuous support.

Reducing the risks of polypharmacy does not mean prescribing less. It means managing better. It implies that someone reviews the whole picture, that the patient understands their treatment, that the caregiver is not alone, and that there is an open channel between those who prescribe, those who dispense, and those who take the medication every day.

The problem of therapeutic adherence and that of polypharmacy are intimately linked. A complex treatment that nobody monitors is a treatment that is followed poorly. And a treatment followed poorly is not just an individual failure: it is a failure of the system that should accompany the patient after every prescription.