Most harm from medicines is not a rare reaction. It is a chain: a drug causes a symptom, the symptom gets its own drug, and nobody ever asks where the chain started.

Follow one chain

Pick a starting point. At each new symptom you decide what happens next — treat the symptom with another prescription, or ask whether the last one caused it. The chains below are composites of the ones that show up in every deprescribing clinic.

Why lists grow and never shrink

• Starting is a two-minute job; stopping is a conversation. A prescription can be added at the end of an appointment. Taking one away needs a review of why it was started, who started it, and what happens if it goes — work that no ten-minute slot contains.
• Nobody owns the whole list. A cardiologist, a urologist, a hospital discharge, an out-of-hours doctor and a pharmacy each add a piece, and each assumes somebody else is looking at the total.
• New symptoms get filed under age. Tiredness, unsteadiness, forgetfulness, constipation and dizziness are all treated as what happens to older people, which is exactly why drug side effects hide there so successfully.
• Guidelines are written one disease at a time. Follow every single-condition guideline for a person with five conditions and you arrive at fifteen drugs, several of which pull against each other. That is a known problem, not your doctor being careless.
• The benefit of some drugs takes years to arrive. A tablet that prevents something a decade from now may not be worth its side effects today, and that arithmetic changes as people get older or frailer — which is a legitimate reason to review, not to quietly stop.
• Patients are polite. People assume the tablet must be necessary, do not want to seem difficult, and often stop taking it silently instead of saying so — which leaves the list wrong on paper and wrong in practice.

The classes worth a second look

These are not bad drugs. They are the ones where the balance most often tips with age, and where a review most often finds something to change. None of them should be stopped without advice.

• Anticholinergics — some bladder tablets, older antihistamines, some antidepressants, drugs for nausea and for muscle spasm. Individually mild, they add up into a burden that dries the mouth, blurs vision, constipates, causes urinary retention and clouds thinking. The total across the list is what matters, and the total is rarely calculated.
• Benzodiazepines and z-drugs for sleep or anxiety. They keep working for a fortnight and then mostly maintain dependence, while measurably increasing falls, fractures, road accidents and confusion. Coming off them is possible but must be slow and planned.
• Opioids for long-term non-cancer pain, where benefit fades and constipation, drowsiness, falls and dependence do not. Chronic back pain is not usually an opioid problem.
• NSAIDs — ibuprofen, diclofenac, naproxen. They raise blood pressure, retain fluid, damage kidneys, cause stomach bleeding and interact with blood pressure tablets, blood thinners and heart failure. The riskiest ones are bought without a prescription.
• Acid-suppressing tablets taken for years without anyone revisiting why they were started, often for a stomach that was only ever irritated by a painkiller which itself has stopped.
• Antipsychotics for distress in dementia, which raise the risk of stroke and death and are specifically dangerous in Lewy body dementia. Occasionally necessary; never a first response and never without a review date.
• Sulfonylureas and insulin aimed at tight sugar targets in a frail person, where a hypoglycaemic episode causes more harm than the number ever prevented.
• Several blood-pressure drugs at once in someone who is now lighter, drier and less steady than when they were prescribed. Dizziness on standing is a reading worth taking sitting and standing.

The brown-bag review, and the five questions

The single most productive appointment available to anybody on multiple medicines: put every box, bottle, inhaler, patch, eye drop, supplement and painkiller from every cupboard into a bag — including what you bought yourself and what you stopped taking — and take the lot in.

1. “What is each of these actually for?” Say it out loud for every box. The answer being unknown is itself a finding, and it happens often.
2. “Is anything on this list treating the side effect of something else on this list?” This is the question that finds cascades, and almost nobody asks it.
3. “What would happen if I stopped this one?” Sometimes the honest answer is nothing much; sometimes it is a hospital admission. Both answers are useful and neither is guessable from the box.
4. “Does this one need a blood test or a blood pressure check, and when was the last one?” Several common drugs need monitoring that quietly lapses over the years.
5. “When is this being reviewed, and can we write that date down?” A drug with no review date tends to become permanent by accident.

Sick days, and the drugs you never stop suddenly

Two opposite rules live in the same subject, which is why both get muddled. Some medicines are paused for a couple of days when you cannot keep fluids down; others are dangerous to stop abruptly at any time.

The half of the list that is not on the list

• Cold and flu remedies routinely contain a painkiller plus a decongestant, so people take paracetamol on top of paracetamol, or a decongestant that lifts blood pressure back up while a tablet pushes it down.
• Paracetamol duplication is the commonest accidental overdose there is: the same drug hides in combination painkillers, hot-drink sachets and night-time preparations under a dozen names.
• Ibuprofen bought for a bad back is the most consequential over-the-counter purchase for anyone with kidney disease, heart failure, high blood pressure, an ulcer history or a blood thinner.
• St John's wort interferes with a long list of prescriptions including some antidepressants, the contraceptive pill, warfarin and transplant drugs. Herbal does not mean inert.
• Grapefruit and grapefruit juice genuinely change the blood levels of several statins, heart drugs and immune medicines. It is worth checking rather than dismissing.
• Alcohol multiplies the sedation of sleeping tablets, opioids and antihistamines, and is part of the fall that gets blamed on the carpet.
• Somebody else's tablets. Sharing painkillers, antibiotics or sleeping tablets within a family is common, invisible on every record, and exactly how the unexplained reaction happens.

Two names, one drug

A large share of double-dosing comes from packaging rather than pharmacology. Most medicines have a chemical name and one or more brand names, generic boxes change shape and colour between batches, and the same tablet can arrive looking entirely different.

• Read the small name, not the big one. The chemical name is the one that tells you whether two boxes are the same drug; the brand is marketing.
• When a box changes appearance, check the chemical name and the strength rather than assuming an error — and check that the old box has actually been removed from the cupboard.
• Keep one list, in one place, with chemical name, strength, how often, and what it is for. A photograph of the list in your phone is worth more in an emergency department than a good memory.
• Beware “when required” drifting into “every day”, which is how a fortnight of sleeping tablets becomes five years.
• Half-tablets, splitting, crushing and opening capsules change how some drugs are absorbed and can be dangerous with slow-release forms. Ask before improvising with a knife.
• Some instructions are pharmacology, not fussiness. Thyroid tablets on an empty stomach, bone tablets upright with a full glass of water, iron away from tea and calcium, some antibiotics away from milk or indigestion remedies. If an instruction seems arbitrary, ask what it is protecting — the answer is usually absorption or the lining of the gullet.
• Slow-release forms must not be crushed or split unless the label says so: breaking them delivers a day's dose at once. If swallowing is the problem, ask for a liquid or a different form rather than reaching for a knife.
• If cost is the reason a box is not being finished, say so. Pharmacists know the cheaper equivalent, the larger pack, the exemption or the scheme, and none of that can be applied to a problem nobody mentioned. Silent rationing of tablets is common and completely invisible on the record.
• One pharmacy, if you can. A single dispensing record is the only place the whole list exists, and it lets the pharmacist catch duplicates and interactions nobody else sees.

Raising it without a fight

The obstacle is rarely disagreement; it is that the conversation never starts. These sentences start it, and they leave the decision where it belongs.

• Bring the symptom, not the accusation. “I have been unsteady since the spring” opens a review; “these tablets are poisoning me” closes it.
• Say when it started relative to the last change. A timeline is the most valuable thing a patient brings, and drug effects usually arrive within days to weeks of a start or a dose increase.
• Ask for one change at a time and a date to check the result. Stopping three drugs at once makes the outcome uninterpretable.
• Do not stop things in the waiting room. Silent non-adherence is understandable and it produces a record that no longer describes reality — which is dangerous the next time somebody prescribes.
• Take somebody with you if the list is long. Two people remember more, and a second voice makes the request harder to defer.
• If a hospital changed everything, book a review with your own doctor within a fortnight of discharge. Discharge letters are where the biggest errors hide, and nobody checks unless somebody asks.

If you are the one keeping an eye

• Watch the two weeks after any change. New confusion, drowsiness, unsteadiness, falls, incontinence or a personality shift after a start or a dose increase is a drug effect until somebody proves otherwise.
• Do the cupboard audit once a year. Expired boxes, duplicates under two names, drugs from a hospital stay that were never stopped, and something prescribed for a person who no longer lives there.
• Count what is actually being taken. A full box at the end of the month is information, not a moral failure — and so is an empty one too soon.
• Make the list travel. One card in the wallet and a photo on your phone; hand it over at every appointment, ambulance and admission without being asked.
• Simplify rather than nag: a weekly dosette box from the pharmacy, fewer doses per day where the doctor can arrange it, and alarms tied to existing routines rather than to the clock.
• Ask about the anticholinergic total if the person you help is drowsy, dry-mouthed, constipated and foggy. It is a specific question with a specific answer, and it is the one most often never asked.

The drill: 16 decisions

Sixteen ordinary moments — a new dizziness, a cold remedy, a discharge letter, a bag of boxes. Most have an instinctive answer that lengthens the list. Pick your move; every answer explains why.

The card

Print it, fill in the list, and keep it in the wallet.

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