Polypharmacy in Older Adults: When Many Medicines Become a Risk

An elderly patient walking into a Dhaka pharmacy with prescriptions from three different specialists, plus a self-bought painkiller and a herbal "tonic," is an everyday scene — and a genuinely risky one. Research tracking adverse drug reactions in older adults found the risk climbs from roughly 6% when someone takes two medicines to about 50% once the count reaches five. That single jump explains why doctors now treat "how many medicines is this patient actually on?" as a clinical question in its own right, not a side note. This is polypharmacy — and in a country where medicines are often bought over the counter without a single doctor coordinating the full list, it deserves far more attention than it gets.

What Is Polypharmacy?

There is no single worldwide definition, but the most widely used threshold — the one the World Health Organization's own literature relies on — is the regular use of five or more medicines at the same time. Some researchers separate this further into "excessive polypharmacy," usually meaning ten or more drugs, which carries even higher risk.

Polypharmacy is extremely common once someone reaches their sixties or seventies. A pooled analysis of 54 studies put the overall prevalence at around 37% among people over 65, and in some hospital settings — one study of elderly patients at discharge found polypharmacy in over three-quarters of prescriptions — the figure is much higher still. In Bangladesh, hospital-based studies have looked at this directly: a cross-sectional study of admitted geriatric patients in a tertiary hospital's medicine ward found that polypharmacy was strongly associated with poor medication adherence and markedly higher odds of dementia among affected patients. A separate outpatient study at a Dhaka hospital used the internationally recognised Beers Criteria to screen elderly patients' prescriptions for medicines considered inappropriate for their age group.

Importantly, polypharmacy itself is not automatically dangerous. Clinicians increasingly distinguish between:

• Appropriate polypharmacy — multiple medicines are genuinely needed and carefully coordinated, and the combined benefit outweighs the combined risk (for example, a patient with diabetes, hypertension, and heart disease who needs several drugs to manage all three safely).
• Problematic polypharmacy — the medicine list includes drugs that duplicate each other, interact dangerously, are no longer needed, or were never clearly indicated in the first place.

The goal is never simply "take fewer pills" — it is making sure every pill on the list is still necessary, still safe at this stage of life, and not quietly working against another medicine on the same list.

Why It Happens, Especially in Bangladesh

Polypharmacy usually builds up gradually, one prescription at a time, rather than being decided all at once. Common drivers include:

• Having multiple chronic conditions — diabetes, high blood pressure, heart disease, kidney disease, arthritis, and thyroid problems often arrive together in later life, and each one tends to come with its own medicine.
• Seeing several different specialists who do not see each other's prescriptions, so no single doctor has the complete picture.
• Adding over-the-counter painkillers, antacids, vitamins, or herbal preparations on top of prescribed medicines, often without mentioning this to any doctor.
• "Prescribing cascades," where a side effect of one drug is mistaken for a new illness and treated with yet another drug, instead of the original medicine being reviewed.

Bangladesh adds a specific layer of risk. Research on pharmacy practice has repeatedly found that a large share of medicines — including ones that should legally require a prescription — are sold directly across the counter by shop staff who are not qualified pharmacists, with no doctor ever reviewing the combination. Surveys also report self-medication is common and rising, particularly for repeat use of medicines for long-term conditions — exactly the pattern that quietly turns into polypharmacy in older adults who may already be seeing more than one doctor.

Who Is Most at Risk

Risk rises sharply with age and with the number of chronic conditions a person is managing. Older adults are also more vulnerable for a reason that is often overlooked: most clinical drug trials are conducted on younger, healthier adults, so dosing guidance for many medicines is extrapolated rather than tested directly on people in their seventies and eighties — whose kidneys, liver, and overall drug clearance work differently. People living alone without a caregiver to help track medicines, people with memory problems, and people who use more than one pharmacy (so no single pharmacist sees the whole list) face the highest practical risk of harmful combinations going unnoticed.

The Risks: What Can Actually Go Wrong

Interactions and adverse drug reactions

Beyond the headline statistic above, polypharmacy is consistently linked in research to medication errors, drug-drug interactions, and preventable adverse drug events — and, in more severe cases, to higher rates of hospitalisation and disability.

Falls and cognitive problems

A study following adults aged 55 and older who had recently had a fall found that taking five or more medicines daily was independently linked to both impaired mobility and impaired overall cognitive function — regardless of how many underlying illnesses a person had or which drug classes were involved. Psychotropic medicines (those affecting mood, sleep, or anxiety) appear especially risky for thinking and movement: one study found measurable effects on cognition, executive function, and mobility with as few as two psychotropic drugs combined.

Non-adherence and confusion

The more medicines on a list, the easier it is to take the wrong one, double a dose, skip one accidentally, or simply lose track of the schedule — especially for someone also managing early memory decline. The Chattogram hospital study mentioned above found this pattern clearly: polypharmacy patients had both poorer adherence and a much higher likelihood of having dementia.

How Doctors Identify Risky Prescriptions

Two internationally recognised screening tools help clinicians spot medicines that are often inappropriate for older patients:

• The Beers Criteria — the most widely used US-developed list flagging specific drugs and drug combinations best avoided, or used with caution, in people over 65.
• STOPP/START — a European tool built from expert consensus, with roughly 80 criteria for medicines to stop (STOPP) and about 34 criteria for beneficial treatments that may have been missed (START).

Studies comparing the two in real clinics have found STOPP/START tends to flag a larger share of inappropriate prescriptions than Beers Criteria alone — in one geriatric clinic study, Beers identified inappropriate prescribing in about a quarter of patients while STOPP flagged it in well over half — which is why many specialists now recommend using both together rather than relying on just one.

Deprescribing: Reducing Medicines Safely

"Deprescribing" is the medical term for the planned, supervised process of reducing or stopping medicines that are no longer helping, or that now carry more risk than benefit at a given age or health stage. It is a deliberate clinical process, never something to attempt alone:

• Start with a full "brown bag" review — bring every medicine the person takes to one appointment, including over-the-counter drugs, vitamins, and herbal products, so the doctor or pharmacist can see the complete picture at once.
• Review the purpose of each drug — ask what each one is for, whether that condition is still active, and whether the medicine is still working as intended.
• Change one medicine at a time — stopping or reducing drugs one at a time makes it possible to notice if a withdrawal effect or returning symptom appears, and trace it to the right medicine.
• Taper rather than stop abruptly where the drug requires it, with a clear monitoring plan afterward.
• Keep the patient involved — this should be a shared decision, not something done to a patient without explanation, since people are often (reasonably) hesitant to give up a medicine they have taken for years.

Evidence shows deprescribing can meaningfully reduce the total number of medicines, adverse reactions, and medication costs. Never stop, skip, or halve a prescribed dose without first discussing it with the prescribing doctor or a pharmacist.

Special Considerations

Dementia and memory problems: Patients with cognitive decline may not reliably report side effects, may take doses incorrectly, and — as the Bangladeshi hospital data above suggests — are disproportionately likely to already be on a long, poorly coordinated medicine list. A caregiver should hold and track the master medicine list for these patients.

Kidney and liver disease: Many drugs are cleared from the body through the kidneys or processed by the liver; when either organ is already under strain from a chronic condition, standard adult doses can build up to unsafe levels. Any elderly patient with kidney or liver disease needs their full medicine list reviewed specifically with this in mind.

Living alone versus with a caregiver: An older adult without daily support is far more likely to lose track of a complex regimen. A simple written or pictorial medicine schedule, reviewed with a family member, meaningfully reduces this risk.

Appropriate Polypharmacy vs. a Problem Medicine List

Not every long medicine list is dangerous, and the two should not be confused:

• A list is more likely appropriate when every drug has a clear, current indication, doses are adjusted for age and organ function, and one doctor or pharmacist has reviewed the complete list for interactions.
• A list is more likely problematic when it includes duplicate drugs from the same class, medicines for a condition that has already resolved, drugs that are known to interact, or anything added without any doctor's knowledge.

Warning Signs That Need Prompt Medical Attention

Seek medical care promptly — rather than waiting for the next routine visit — if an older adult on multiple medicines develops any of the following: new or worsening confusion, unusual drowsiness or difficulty staying awake, a fall or sudden unsteadiness, unexplained bruising or bleeding, a noticeably irregular or very slow/fast heartbeat, persistent vomiting, or a marked change in alertness after a new medicine is started. These can all be signs of a drug interaction or an adverse reaction and should not be dismissed as "just old age."

Prevention: Keeping a Medicine List Safe

• Use one pharmacy (or at least one pharmacist who knows the full list) wherever possible, so interactions are more likely to be caught.
• Bring every medicine — prescribed, over-the-counter, and herbal — to every doctor's visit, not just the ones being newly prescribed.
• Ask for a full medication review at least once a year, or sooner after any hospital stay, new diagnosis, or new prescription.
• Avoid buying prescription-only medicines directly from a pharmacy counter without a doctor's review, however convenient it feels in the moment.
• Keep one written, updated list — drug name, dose, purpose, prescribing doctor — that travels with the patient to every appointment.

None of this replaces individual medical advice. Every decision about starting, changing, or stopping a medicine for an older adult should be made with their doctor or a qualified pharmacist, who can weigh their specific conditions, kidney and liver function, and full medicine list together.

Sources: Peer-reviewed research on polypharmacy definitions and outcomes in older adults, the American Geriatrics Society's Beers Criteria and the STOPP/START prescribing-screening framework, the World Health Organization's polypharmacy definition, and hospital-based studies on geriatric polypharmacy and medicine dispensing practices in Bangladesh.