Pharmacology

Polypharmacy & Drug
Interaction Management

WestNet Medical • Module 06 • Deprescribing & Iatrogenic Harm

WestNet Unified Health Platform • WestNet Catalog 731985456611 • ISBN 978-0-XXXXX-XXX-X (Pending)
CE Accreditation Path: ANCC • ACCME • CARNA
Last updated: June 2026

Core Learning Objective

Learners will reverse the reflexive habit of adding a drug for every symptom and instead practice active, skilled stewardship: reconcile across transitions, recognize the prescribing cascade, quantify anticholinergic burden, and deprescribe systematically — so that fewer, better-chosen medicines restore the whole person rather than suppress them.

Published By

WestNet Medical Publications
A division of WestNet North America Inc.
medical.westnet.ca

Co-Published With

WestNet Humanitarian Services (WHS)
UN Supplier • Registered NGO
www.westnet.ngo

WestNet Catalog (UPC-A): 7 31985 45661 1
ISBN 978-0-XXXXX-XXX-X (Pending) • First Edition

7 31985 45661 1

WestNet Medical Publications

Continuing Education Information

Field	Detail
Module	06 of 12 — Pharmacology
Contact Hours	3.0 (Pending ANCC / ACCME / CARNA approval)
Target Audience	RNs, LPNs, RPNs, NPs, Pharmacists, Pharmacy Technicians, Physicians, PAs, and Clinical Educators
Publication	WestNet Medical Publications • Catalog 731985456611 • ISBN Pending
Disclosure	Educational content. Does not replace facility formulary policy, prescriber judgment, or jurisdictional scope-of-practice requirements. Drug examples are illustrative.

Perform structured medication reconciliation at every transition of care
Identify high-risk medication classes using the Beers Criteria and STOPP/START framing
Recognize the prescribing cascade — a drug side effect mistaken for a new disease and treated with another drug
Quantify cumulative anticholinergic burden and link it to cognitive and falls risk using the ACB tool
Apply a stepwise deprescribing framework: review indication, weigh risk vs benefit, prioritize, and taper
Design safe taper plans and distinguish withdrawal effects from disease recurrence
Communicate medication concerns to prescribers using SBAR

Program Preface

§ 01

This module was developed from medication-use review across North American primary care, hospital, and long-term care settings — not from textbook pharmacology alone. WestNet HealthOS surfaces every active medication a person is taking across every prescriber, because the most dangerous drug interaction is often the one no single clinician can see from inside one chart.

Module 06 is not anti-medication. Medicines, used well, are among the great achievements of clinical care. It is anti-thoughtless accumulation — the slow, well-intentioned drift in which each new symptom earns a new prescription, no one ever revisits the old ones, and a person ends up on twelve drugs that quietly work against one another.

WestNet Position

The default reflex of the system is to add, not to subtract. Every guideline names a drug to start; almost none name the moment to stop. Deprescribing is the missing half of good prescribing — an active, skilled, evidence-based intervention, not the absence of care.

The Reflex: Add, Never Subtract

§ 02

Polypharmacy — commonly defined as the routine use of five or more medications — is not in itself a diagnosis. The problem is inappropriate polypharmacy: drugs that no longer have an indication, that duplicate one another, that treat the side effect of another drug, or whose risk has quietly outgrown their benefit as the person aged and their physiology changed.

Clinical Reality

Each medication added to a regimen multiplies the chance of an interaction, an adverse event, and a new symptom that looks like a new disease. The risk of a clinically significant interaction rises steeply — not linearly — with each additional drug. More is not safer. More is simply more.

The Question the System Forgets

When an older adult arrives confused, unsteady, constipated, dizzy, or low in mood, the disciplined first question is rarely asked: “Is the drug causing this?” The reflex is to name a new condition and reach for a new prescription. Asking the question first is not skepticism toward medicine — it is the highest form of respect for it.

The Four Pillars of WestNet Medication Stewardship

§ 03

Pillar I

Reconcile Completely

Know every drug the person actually takes — prescribed, over-the-counter, herbal, and borrowed — across every prescriber. The list in the chart is a hypothesis until you have verified it with the patient.

Pillar II

Ask If The Drug Is The Cause

Before naming a new disease, rule out the medications already on board. A new symptom in a person on many drugs is a side effect until proven otherwise.

Pillar III

Subtract With Skill

Deprescribing is active care, not neglect. Review each drug's indication, weigh current risk against current benefit, and plan a taper. Stopping a drug safely is as skilled as starting one.

Pillar IV

Restore The Person

The goal is not an empty medication list — it is the right list. Fewer, better-chosen medicines return clarity, balance, appetite, and dignity. The aim is to make the human human again.

How Drugs Move & Act: PK & PD Basics

§ 04

Before any interaction or adverse effect makes sense, two ideas have to be in the room. Pharmacokinetics (PK) is what the body does to the drug — absorption, distribution, metabolism, and elimination (the “ADME” sequence). Pharmacodynamics (PD) is what the drug does to the body — the effect at the receptor or target. Most polypharmacy harm is a PK problem (a drug builds up because it cannot leave) or a PD problem (two drugs push the same physiological lever in the same direction).

Absorption

How much of a dose reaches the bloodstream, and how fast. Altered by gut motility, food, gastric pH, and binding interactions (e.g. a mineral that chelates an antibiotic so neither is absorbed).

Distribution

Where the drug travels — fat, muscle, water, protein-bound vs free. Aging shifts body composition (less water, more fat, less albumin), changing how long a drug lingers and how much is active.

Metabolism

Chemical transformation, mostly hepatic (the CYP450 system, §06). One drug can speed up or block the enzyme that clears another — the engine of most interaction warnings.

Elimination

Clearance from the body, mostly renal. As kidney function falls with age or illness, renally-cleared drugs accumulate — the same dose becomes a rising dose (§05).

Why the Same Dose Is Not the Same Dose

A standard dose is calibrated for an average, younger physiology. In an older or frailer person — lower lean mass, less albumin, reduced renal clearance, a slower liver — that same milligram can produce a higher concentration and a longer effect. The label did not change; the person did. This is why “start low, go slow” is not timidity but pharmacology.

Two concepts make PK practical at the bedside. Half-life is the time for the drug concentration to fall by half; it takes roughly four to five half-lives for a drug to clear — or to reach steady state once started. A long half-life means a drug lingers long after the last dose, so harm can appear or persist days later. The therapeutic index is the gap between an effective dose and a toxic one: drugs with a narrow index (the difference between “working” and “harmful” is small) leave little room for the shifts above and demand the most caution.

Interactive Clinical Partner

Half-Life & Accumulation Explorer

Slide to set a drug’s elimination half-life, then see how long it takes to clear after the last dose (about 4–5 half-lives) and to reach steady state on regular dosing. This illustrates a principle — it is not a dosing calculator. Verify all dosing against current product information and local protocols.

Elimination half-life: 12 hours

~50 h

Practical clearance window

A long half-life is a double-edged sword: steadier levels, but harm and interactions persist long after a dose is missed or stopped. When clearance slows (renal or hepatic impairment, §05), the effective half-life lengthens and the same regimen quietly accumulates.

Renal & Hepatic Dosing Principles

§ 05

The two organs that clear most drugs — the kidney and the liver — are also the two whose function quietly declines with age and disease. When clearance falls, the dose that was once safe becomes a slow overdose. Dose adjustment for organ function is among the highest-yield safety steps in all of medication management, and one the “add a drug” reflex routinely skips.

The Silent Accumulation

Renal and hepatic decline are usually silent — no symptom announces them until a drug has already built up. A renally-cleared drug given at full dose to someone with reduced kidney function does not fail loudly; it accumulates quietly, dose after dose, until confusion, bleeding, low blood sugar, or a rhythm disturbance appears and is mistaken for a new disease.

Renal

Estimate, Don’t Assume

A “normal” serum creatinine can hide poor function in a small, older, low-muscle person. Use an estimate of kidney function (eGFR / estimated creatinine clearance), not creatinine alone, when judging renally-cleared drugs.

Renal

Know the Renally-Cleared

Many common agents depend on the kidney to leave the body — certain antimicrobials, some anticoagulants, gabapentinoids, metformin, digoxin, lithium, and more. For these, falling renal function means a falling safe dose. Verify each against current product information.

Hepatic

Respect the First-Pass Liver

The liver metabolises most drugs and runs the CYP450 system (§06). In hepatic impairment, drug levels can rise, clotting factors fall, and sedatives hit harder. Sedating and anticoagulant agents deserve particular caution.

Both

Re-check When Status Changes

Acute illness, dehydration, heart failure, or a new interacting drug can drop clearance overnight. A dose that was right last month may be wrong today. Re-assess organ function whenever the clinical picture shifts.

Practical Discipline

For any new or continued drug in an older adult, ask three questions: Is this drug cleared by the kidney or the liver? Is that organ working well today? Does the dose reflect the answer? Where a drug has a narrow therapeutic index and organ-dependent clearance — the dangerous combination — treat every dose decision as deliberate, and confirm it against current local protocols.

Connect It Back

Reduced clearance lengthens half-life (§04) and amplifies interactions (§06): a drug that is both renally cleared and dependent on an enzyme another drug blocks can accumulate from two directions at once. This is why the frail, multi-drug, multi-morbid patient is exactly the person in whom “just add one more” is most likely to cause harm.

How Interactions Happen: CYP450 & Mechanisms

§ 06

“Drug interaction” is not magic — it is mechanism. Most clinically important interactions fall into a small number of patterns. Recognising the pattern tells you what to expect, what to monitor, and how soon. The single most common engine is the liver’s cytochrome P450 (CYP450) enzyme family, which metabolises a large share of all medications.

PK — metabolism

CYP450 Inhibition

Drug A blocks the enzyme that clears Drug B. Drug B’s level rises — toward toxicity. Inhibition is often fast (within a dose or two). A potent inhibitor added to a narrow-index drug is a classic harm setup.

PK — metabolism

CYP450 Induction

Drug A speeds up the enzyme that clears Drug B. Drug B’s level falls — toward treatment failure. Induction is usually slow (days to weeks) and, dangerously, reverses slowly too when the inducer is stopped.

PK — absorption

Binding / Chelation

One agent physically binds another in the gut so neither is absorbed — e.g. a mineral or antacid and certain antibiotics or thyroid medication. Often solved simply by separating the doses in time.

PK — transport

Transporter & Renal Competition

Drugs can compete for the same transport proteins (e.g. P-glycoprotein) or for renal excretion, so one slows the other’s exit and raises its level. Same result as inhibition, different doorway.

PD — additive

Additive / Synergistic Effect

Two drugs push the same lever — two sedatives, two QT-prolongers, two serotonergic agents, two that lower blood pressure or blood sugar. No metabolism is altered; the effects simply stack, sometimes dangerously.

PD — opposing

Antagonism

One drug undoes another — an anticholinergic blunting a drug given for dementia, or an NSAID opposing an antihypertensive. The treatment quietly fails, and the dose is often pushed higher instead of the conflict being seen.

The Grapefruit Principle

Interactions are not limited to drug-on-drug. Foods, juices, and botanicals act through the very same enzymes — the textbook example being grapefruit, which inhibits an intestinal CYP enzyme and can raise the level of several medications. The lesson generalises: anything that touches CYP450 — drug, food, or supplement — can shift a drug’s level. (Herbs and supplements get their own section, §16.)

Interactive Clinical Partner

Interaction Mechanism Demonstrator

Pick a mechanism to see, in plain terms, what happens to the affected drug’s level, how fast, and what to watch for. This teaches the pattern of an interaction — it is not a substitute for a current, validated drug-interaction checker. Always verify a specific pair against an up-to-date reference and local protocols.

—

Select a mechanism

Choose one of the interaction mechanisms above to see its effect, its speed of onset, and the clinical watch-points.

Tip: the most dangerous interactions combine a narrow-therapeutic-index drug with a potent inhibitor, or stack two drugs that push the same physiological lever.

Medication Reconciliation Across Transitions

§ 07

Transitions of care — admission, transfer, discharge, a new specialist — are where medication errors are born. A drug is held in hospital and never restarted; a discharge prescription duplicates a home medication under a different brand name; a dose changed on the ward reverts at home. Reconciliation is the disciplined, three-step process that closes those gaps.

Step 1

Collect (Best Possible History)

Build the Best Possible Medication History from at least two sources: the patient or caregiver, the pharmacy record, the bottles themselves. Ask about inhalers, eye drops, patches, PRNs, supplements, and anything bought without a prescription.

Step 2

Compare

Line the verified history up against the orders at this transition. Flag every discrepancy: omissions, duplications, dose or frequency changes, and drugs with no documented reason.

Step 3

Reconcile & Communicate

Resolve each discrepancy with the prescriber — intentional or error? Document the rationale, and hand the patient a clear, current list in plain language they can actually use at home.

Always

Indication For Every Drug

If no one on the team can state why a medication is being taken, that is the first candidate for review. “It was on the list” is not an indication.

Practical Tip

Brown-bag review — asking the patient to bring in every bottle, box, and blister pack — routinely uncovers duplicate therapies, expired drugs, and medications no one knew were still being taken. It is among the highest-yield five minutes in clinical care.

“Natural” Still Belongs on the List — A Reconciliation Safety Point

The most commonly omitted items in a medication history are the ones the patient does not consider “medications” — herbal products, teas, and supplements. Botanicals are not free of pharmacology. A working teaching example is dandelion (Taraxacum officinale), widely taken as a tea or supplement: its mild diuretic effect means it may plausibly interact with lithium (reduced clearance → rising levels), potassium and prescription diuretics (additive fluid and electrolyte shifts), and some antidiabetic agents (possible added glucose-lowering). The clinical evidence for these specific interactions is preliminary^[6] — the durable lesson is the principle: a product being “natural” does not place it outside medication reconciliation. Ask about it, record it, and check it like any other agent. Verify any suspected interaction against current local protocols and an up-to-date interaction reference.

Reconciliation also lives or dies on how the question is asked. A rushed “you’re still on the same meds, right?” invites a yes; an open, non-judgmental prompt surfaces the inhaler, the borrowed pill, and the bedtime tea. The script below opens the conversation without putting the patient on the defensive.

Open the list

Ask Widely, Without Judgment

Name the categories people forget, and signal that “natural” and occasional items count too — so they are volunteered, not hidden.

Say: “Help me build your full list. Besides your prescriptions, what do you take that you buy yourself — vitamins, herbal teas, supplements, pain or sleep aids, anything occasional?”

Confirm the truth

Verify Against the Bottles

Reconcile what is actually taken against what is charted, naming any gap as shared problem-solving rather than a test the patient can fail.

Say: “Can we go through the bottles together? I want to make sure my list matches exactly what you really take — including anything you’ve stopped or only use now and then.”

Avoid

What Not to Say

Leading or dismissive phrasing teaches the patient to under-report — and the omitted item is often the one that matters.

Avoid: “Same as last time?” • “That herbal stuff doesn’t count.” • “Just the real medications, please.”

Recognising an Adverse Drug Event

§ 08

An adverse drug event (ADE) is harm that comes from a medication — whether from the drug itself (an adverse drug reaction), from an interaction, from an error, or from a dose that has outgrown the person. ADEs are a leading cause of emergency visits and hospital admissions in older adults, and a large share are preventable. The difficulty is not that they are rare — it is that they disguise themselves as ordinary illness or “just getting older.”

The Great Imitator

Almost any common geriatric presentation — a fall, confusion, dizziness, constipation, incontinence, fatigue, low mood, poor appetite, a new tremor — can be the face of an adverse drug event. The disciplined clinician treats these not as diagnoses but as questions, and the first question is always the same: could a medication be causing this?

A structured way to decide whether a drug is the culprit is to weigh a few features of the link between the medicine and the symptom — the logic behind formal causality tools, distilled for the bedside:

Timing

Did the symptom begin after the drug was started or increased? A clear temporal sequence — new confusion three days after a dose change — is the strongest everyday clue.

Plausibility

Is this a known effect of this drug or class? An anticholinergic causing dry mouth and confusion is biologically expected; check the profile before dismissing the link.

Dechallenge

Does the symptom ease when the drug is reduced or stopped? Improvement on withdrawal is powerful evidence — provided you allow for the drug’s half-life (§04) before judging.

Alternatives

Is there a better explanation — a true new illness, dehydration, infection? ADE is a leading hypothesis, not the only one; rule it in and rule the others out.

Type A vs Type B

Most ADEs are Type A (“augmented”) — an exaggeration of the drug’s known effect, dose-related and predictable, and therefore preventable by dose, choice, and review. A minority are Type B (“bizarre”) — idiosyncratic reactions such as true allergy, unrelated to dose and harder to foresee. The everyday work of this module is overwhelmingly about the preventable Type A events that the “add a drug” reflex creates.

Report So the System Learns

Recognising an ADE in front of you protects this patient; reporting it protects the next thousand. Document the event and the temporal link, tell the prescriber via SBAR (§23), and submit to the relevant pharmacovigilance program where one exists. Surveillance is how rare and serious reactions are ever discovered. Follow local reporting policy.

High-Risk Classes & the Beers Criteria

§ 09

The American Geriatrics Society Beers Criteria catalogue medications that are potentially inappropriate in older adults — where the risk of harm typically outweighs the benefit, or where a safer alternative exists.^[1] The European STOPP/START criteria pair drugs to stop with treatments that are often wrongly omitted.^[2] Neither is a list of forbidden drugs; both are prompts to think.

Class	Why It Carries Risk	Watch For
Benzodiazepines & Z-drugs	Sedation, impaired balance, dependence, slowed cognition; effects amplified with age.	Falls, daytime confusion, memory complaints.
Anticholinergics	Block acetylcholine system-wide; burden is cumulative across many common drugs (see §06).	Confusion, dry mouth, constipation, urinary retention, falls.
Antipsychotics (in dementia)	Used for behavioural symptoms despite an increased risk of stroke and death; rarely a first-line answer.	Sedation, rigidity, falls; ask what the behaviour is communicating.
NSAIDs (long-term)	GI bleeding, kidney injury, fluid retention, raised blood pressure — risk rises with age and other drugs.	New hypertension, edema, rising creatinine, black stools.
Sulfonylureas (long-acting)	Prolonged hypoglycemia in older adults, often mistaken for confusion or a “mini-stroke.”	Sweating, confusion, falls, especially if meals are missed.
Proton-pump inhibitors	Frequently continued indefinitely with no remaining indication; not benign over years.	The original reason is gone but the drug remains — a deprescribing candidate.

How To Use These Tools

Beers and STOPP/START are decision supports, not mandates. A drug on the list is not automatically wrong — it is a flag that says: stop and justify this, in this person, today. The criteria exist precisely because the default never pauses to ask.

A flag is not a decision. Once a drug is flagged — by Beers, by STOPP, by a high ACB weight, or simply by a new symptom — the pathway below converts the flag into a concrete next step. It is a structured prompt, not a substitute for clinical judgment; confirm every taper and switch against current local protocols.

Myth vs Evidence

×Myth: “More medications means more thorough care.”
Evidence: Beyond what is genuinely indicated, each added drug raises the risk of interactions and adverse events without adding benefit. More drugs is not more care — the right drugs are.
×Myth: “A new symptom needs a new treatment.”
Evidence: In a person on several drugs, a new symptom is frequently the side effect of an existing one. Treating that side effect with another drug is the prescribing cascade. Treat the cause — reach for the drug list before the prescription pad.
×Myth: “If it’s on the Beers list, the drug is forbidden.”
Evidence: Beers and STOPP/START flag drugs to justify, not to ban. The aim is never to label or punish a regimen — it is to treat the person, not the list, by re-asking whether each agent still earns its place today.

Related WestNet Medical Module

Antipsychotics for behavioural symptoms in dementia are a recurring high-risk example here. For the non-drug, root-cause alternative — asking what the behaviour is communicating before reaching for a sedating agent — see Module 07 — Iatrogenic Harm & De-escalation.

High-Alert Medications

§ 10

Not every drug carries the same stakes. High-alert medications are those that bear a heightened risk of causing significant harm when they are used in error. The errors are not necessarily more frequent — but when they happen, the consequences are severe. These agents earn extra safeguards by design, not by suspicion.

High-Alert Category	Why It Demands Extra Care	Safeguard Principle
Anticoagulants	A narrow margin between preventing a clot and causing a bleed; many interactions and a strong food/organ-function dependence.	Verify indication, dose, and interactions at every change; monitor where required.
Insulin & insulin secretagogues	Errors cause hypoglycemia — confusion, falls, seizure — often mistaken for a neurological event in older adults.	Independent double-check of dose; align with meals; never assume “more is better.”
Opioids & sedative combinations	Respiratory depression, especially when stacked with benzodiazepines or other CNS depressants (additive PD effect).	Lowest effective dose, screen for overlapping sedatives, plan the taper (see §21).
Concentrated electrolytes (e.g. potassium)	Wrong concentration or route can be rapidly fatal.	Strict storage, labelling, and administration controls.
Narrow-therapeutic-index drugs (e.g. digoxin, lithium, certain antiseizure drugs)	The gap between effective and toxic is small; small PK shifts (renal decline, interactions) tip into toxicity.	Know the target range, monitor levels, re-check when organ function or co-medication changes.
Chemotherapy & immunosuppressants	Severe toxicity; complex, time-critical regimens where a single error compounds.	Specialist verification; never adjust outside the governing protocol.

The Compounding Danger

The greatest hazard arises where two risk factors meet: a high-alert, narrow-index drug and a setting that erodes its margin — reduced renal or hepatic clearance (§05), a new CYP450 interaction (§06), or an unrecognised duplicate. In these patients, “routine” is the wrong posture. Slow down, verify, and confirm against current local protocols.

Look-Alike, Sound-Alike

A distinct error source is the confusion of drug names — look-alike, sound-alike pairs — and of similar packaging or strengths. Among high-alert drugs this is especially dangerous. Confirm the right drug, dose, route, time, and patient, and treat any name you are unsure of as a stop-and-check, not a guess.

Drug-Class Deep Dives

§ 11

The classes below recur throughout this module as both common offenders and common deprescribing candidates. For each, the question is never “is this drug bad?” but “does this drug still earn its place in this person, today?” Doses are deliberately omitted — the principle travels; the numbers must always be verified against current product information and local protocols.

Benzodiazepines & Z-Drugs

Effective for short-term, specific problems; harmful as a standing solution for chronic insomnia or anxiety in older adults. They blunt balance and cognition, build tolerance and dependence, and are a leading driver of falls and “confusion” that masquerades as dementia. Cannot be stopped abruptly — a planned taper is mandatory (§20).

Proton-Pump Inhibitors (PPIs)

Valuable for clear indications (active ulcer disease, certain reflux, protection alongside high bleed-risk drugs). The problem is indefinite continuation after the reason has passed — the classic “started in hospital, never stopped” drug. Most candidates can be stepped down or stopped, some after a brief taper to avoid rebound acid.

NSAIDs

Among the highest-risk classes in older or multi-morbid patients: GI bleeding, kidney injury, fluid retention, raised blood pressure, and heart-failure decompensation. They also antagonise antihypertensives (a PD interaction, §06). Often a strong candidate for the safest effective alternative rather than ongoing use.

Antipsychotics (for behaviour in dementia)

Associated with increased stroke and mortality risk when used for the behavioural symptoms of dementia, and rarely a first-line answer. Ask what the behaviour is communicating — pain, fear, infection, an unmet need, or another drug — before reaching for a sedating agent. (See the non-drug alternatives in Module 07.)

Cardiovascular & Glucose-Lowering Agents

Often genuinely beneficial — but benefit and harm both shift with age, frailty, and goals of care. Tight targets that made sense at 60 can cause hypotension, falls, or hypoglycemia at 85. Re-judge the target, not just the drug: the right intensity for the person in front of you.

The Common Thread

Every class above is sometimes exactly right and sometimes long past its purpose. The skill this module builds is not memorising villains — it is the habit of re-asking indication, re-weighing risk against benefit for this person today, and being willing to subtract.

Interactive Knowledge Check

Drug-Class Quick Quiz

Three questions on the classes above. Choose an answer to see immediate feedback and the reasoning. This is formative practice, not the graded competency assessment (§29).

Answers reinforce principles, not protocols. Confirm every class-specific decision against current local guidance.

Anticholinergic Burden — The Hidden Sum

§ 12

Many ordinary, individually-tolerated medications carry mild anticholinergic activity — some antihistamines, bladder drugs, tricyclic antidepressants, certain antipsychotics, and more. No single one looks alarming. But anticholinergic effects are cumulative: three “mild” drugs together can produce the confusion, constipation, dry mouth, blurred vision, urinary retention, and falls of one strong one. A higher cumulative burden is associated with greater cognitive decline and falls risk in older adults.

The danger is invisible from inside any one prescription. Only when you add the whole regimen together does the burden appear — which is exactly why the reflex misses it, and why the question must always be: is the drug causing this?

The Anticholinergic Cognitive Burden (ACB) Scale

Each anticholinergic drug is scored 1 (possible/mild), 2 (definite/moderate), or 3 (definite/marked). The scores are summed. A total of 3 or more is associated with clinically meaningful cognitive and physical risk — and is a clear prompt to review.

Interactive Clinical Partner

Anticholinergic Burden (ACB) Calculator

Select each anticholinergic medication the patient is currently taking. The tool sums the cumulative ACB score in real time and reads out the associated cognitive and falls risk. Weights follow the published ACB scale (1 = mild, 2 = moderate, 3 = marked). This is a teaching aid — it never replaces a full medication review or clinical judgment.

No anticholinergic burden

Nothing selected. Add the patient's current anticholinergic medications to see the cumulative burden.

Cumulative burden ≥ 3 is associated with measurable cognitive impairment and increased falls risk. The most effective intervention is usually subtraction: can a high-burden drug be stopped, lowered, or swapped for a non-anticholinergic alternative?

Anticholinergic Burden in Depth

§ 13

The calculator in §12 makes the burden visible; this section explains why it matters so much and how to act on it. Acetylcholine is a workhorse neurotransmitter — it runs memory and attention in the brain, keeps the gut and bladder moving, controls salivation and sweating, and helps regulate heart rate. Anticholinergic drugs block it. A little blockade from one drug is usually tolerated; blockade summed across several drugs produces a recognisable, system-wide syndrome.

System	Anticholinergic Effect	How It Presents — and Is Misread
Brain	Reduced acetylcholine signalling	Confusion, memory loss, delirium — misread as new or worsening dementia.
Eyes	Pupil dilation, impaired focus	Blurred vision, falls — misread as failing eyesight or clumsiness.
Mouth / glands	Reduced secretions	Dry mouth, poor appetite, dental decay — misread as “just ageing.”
Gut	Slowed motility	Constipation, even obstruction — earns a laxative (a cascade, §14).
Bladder	Reduced contraction	Urinary retention, overflow — ironically often caused by a bladder drug.
Heart / skin	Raised heart rate, reduced sweating	Palpitations, overheating — a real heat-illness risk in summer or fever.

The Self-Reinforcing Trap

Anticholinergic burden is a cascade waiting to happen. The dry mouth earns a sugary lozenge; the constipation earns a laxative; the confusion earns a workup or even an antipsychotic; the retention earns a catheter. Each “treatment” adds complexity while the true cause — the summed blockade — goes unexamined. The fix is almost always subtraction, not addition.

Use the checklist below to tally a regimen the way a reviewer would: identify every contributor, note its weight band, and let the running total speak. It mirrors the §12 calculator but is organised by where drugs hide — so the easily-forgotten over-the-counter and “simple” agents are caught.

Interactive Clinical Partner

Where the Burden Hides — Tally Checklist

Tick each source present in the regimen. The running tally groups drugs by where they are most often overlooked — the OTC sleep aid and the “harmless” allergy pill count just as much as the prescription. Weights are illustrative (high = 3, moderate = 2, low = 1); verify specific agents against a published ACB scale.

No burden identified

Tick the sources present to total the hidden burden.

If the total reaches 3 or more, the regimen warrants active review for substitution or deprescribing — especially where confusion, falls, constipation, or retention are already present.

Deprescribing Toward a Lower Burden

The intervention is rarely “stop everything.” It is targeted: swap the sedating antihistamine for a non-sedating or non-drug alternative, reconsider whether the bladder antimuscarinic is helping, and choose lower-burden options within a needed class. Each single substitution can drop the total below the risk threshold and lift the syndrome — verify alternatives against current local protocols.

The Prescribing Cascade

§ 14

The prescribing cascade is the single most preventable engine of polypharmacy. It begins when an adverse drug effect is misread as a new medical condition. A second drug is prescribed to treat it. That drug causes its own effect, which earns a third drug — and so a person accumulates a regimen built not on diseases, but on the side effects of their own treatment.^[4]

A Classic Cascade

A drug for one condition raises blood pressure → an antihypertensive is added → it causes ankle swelling → a diuretic is added → the diuretic provokes gout → a gout drug is added. Four drugs now treat the consequences of the first. None of it was a new disease.

Case Vignette

An 80-year-old is started on amlodipine for blood pressure. Weeks later she develops ankle edema — read as a new problem, so a diuretic is prescribed. The diuretic drives urinary frequency; she becomes incontinent, rushes to the toilet at night, and falls. The falls and incontinence earn yet another drug. At each step a side effect of the last drug was mistaken for a fresh disease, and the regimen grew.

Resolution: someone finally recognizes the prescribing cascade and asks the disciplined question — “is the drug causing this?” The amlodipine is identified as the first link and stopped; with the offending agent gone, the edema resolves and the downstream drugs — diuretic and the rest — can be deprescribed in turn. Subtract the culprit, and the whole chain falls away.

WestNet Protocol

The cascade is broken at its first link by a single discipline: when a new symptom appears in a person already on medication, treat “adverse drug effect” as the leading hypothesis — not the last resort. Subtract the suspect before you add a successor.

Clinical Pearls

•Before adding any drug for a new symptom, ask first: “is a medication causing this?” — make adverse drug effect the leading hypothesis, not the afterthought.
•Use Beers and STOPP/START to flag high-risk medicines in older adults — they are prompts to stop and justify a drug in this person today, not lists of forbidden agents.
•Cumulative anticholinergic burden drives falls and cognitive decline — three “mild” agents can add up to one strong one; sum the whole regimen, never judge a single prescription.
•Deprescribing is active care, not withdrawal of care — taper gradually with a written plan; do not stop a taper-requiring drug abruptly.

Cascade Explorer — Walk the Chain, Find the Off-Ramp

§ 15

This is a composite cascade assembled from recurring real-world patterns — no single patient. Tap through each step to see the drug, the harm it caused, and the question that would have stopped the chain. The final step is the deprescribing off-ramp: the exit available at every link if anyone had asked, “is the drug causing this?”

Step 1 of 6

The drug & the move

The harm it caused

The question that breaks it

The Off-Ramp Exists At Every Step

The cascade is not inevitable. At each link, one question — “could a medication be causing this?” — opens an exit. Deprescribing the first culprit can collapse the entire chain that followed it.

Herb & Supplement Interactions

§ 16

Reconciliation (§07) insisted that “natural” products belong on the list. This section explains why they matter pharmacologically. Botanicals, vitamins, and supplements are chemically active — they act through the same enzymes, transporters, and receptors as prescription drugs (§06). Patients frequently do not disclose them, assuming they “don’t count,” and the interactions they cause are therefore among the most invisible in all of medication safety.^[6]

Three Reasons They Are Dangerous

1. Under-reported — patients omit them, so they are absent from the chart. 2. Variable — potency and even contents differ between products and batches, so the “dose” is uncertain. 3. Mechanistically real — they genuinely induce or inhibit drug-metabolising enzymes, add to bleeding or sedation, or shift drug levels. “Natural” is a marketing word, not a pharmacological category.

Interaction Pattern	Illustrative Mechanism	What to Watch / Ask
Enzyme induction (faster clearance)	Some popular botanical mood/energy products can induce CYP enzymes, lowering the level of co-prescribed drugs toward failure.	Unexplained loss of effect of a prescription drug after a supplement is started; ask what was added.
Added bleeding risk	Several supplements taken for circulation or joints have mild antiplatelet or anticoagulant effects that add to prescription blood thinners (a PD interaction).	Bruising or bleeding; review before procedures; reconcile alongside anticoagulants.
Added sedation	Botanical “calming” or sleep products can deepen the sedation of benzodiazepines, opioids, and antihistamines.	Daytime drowsiness, falls, confusion — sum the sedative load just like ACB.
Electrolyte / fluid shifts	Diuretic or laxative botanicals (the dandelion principle from §07) and high-dose minerals can shift potassium, sodium, and hydration.	Reconcile against diuretics, lithium, and glucose-lowering agents; verify any suspected pair.
Mineral / drug binding	High-dose minerals (calcium, iron, magnesium) can bind certain antibiotics and thyroid medication in the gut, blocking absorption.	Separate dosing in time; suspect when a reliable drug suddenly “stops working.”

The Reconciliation Habit

Treat every supplement as a drug: name it, record the actual product and dose, and check it against the regimen using a current interaction reference. The clinical evidence for many specific herb–drug interactions is still emerging; the safe posture is not alarm but inclusion — ask, document, and verify, exactly as you would for any prescription agent. Verify against current local protocols.

The same reflexes that defend an unneeded drug also dismiss a relevant supplement. Tap each card to flip the reflexive assumption into the safer stance.

Bottom Line

You cannot check an interaction you never recorded. The single most protective act is simply to ask, without judgment, about everything the person takes — and to mean it when you say the herbal tea counts.

The Deprescribing Framework

§ 17

Deprescribing is the planned, supervised process of reducing or stopping medications that may be causing harm or no longer providing benefit, with the goal of improving outcomes. It is a clinical intervention with its own evidence base — not simply “not prescribing.” The framework below is a disciplined, repeatable sequence.

Step 01

Compile the Full List

Reconcile every medication and its actual indication. You cannot deprescribe what you have not first reconciled. Include OTC, herbal, and PRN agents.

Step 02

Review Each Indication

For every drug ask: is there still a valid reason for this? Has the original condition resolved, or the evidence changed? A drug without a current indication is the first to question.

Step 03

Weigh Current Risk vs Benefit

Re-assess in this person, today: age, kidney and liver function, frailty, life expectancy, and goals of care all shift the balance. A benefit that took years to appear may no longer be reachable.

Ask: “Would I start this drug in this patient today?”

Step 04

Prioritise What to Stop

Rank candidates by harm and lack of benefit. Start with the highest-risk, lowest-value drug — and change one thing at a time so the effect is interpretable.

Step 05

Plan the Taper

Many drugs cannot be stopped abruptly. Build a gradual, written taper schedule, and tell the patient exactly what to watch for and who to call.

Step 06

Monitor & Support

Follow up. Distinguish withdrawal effects from genuine recurrence. Reassure, adjust, and document. Deprescribing is a relationship over time, not a single act.

Shared Decision-Making

Deprescribing is done with the patient, never to them. Explain why, invite their goals, and respect that some will choose to continue a drug. The aim is the regimen that best serves the person — as they define a good life.

The WestNet Deprescribing Ladder

§ 18

Rung 1

Reconcile & Find the Indication

Verify the complete, current list. For each drug, state the reason out loud. No reason found → first review candidate.

Rung 2

Ask: Is a Drug the Cause?

Screen every new symptom against the regimen. Map confusion, falls, dizziness, constipation, or low mood to likely culprits before naming a new disease.

Rung 3

Weigh Risk vs Benefit Today

Re-judge each flagged drug for this person now — frailty, kidney function, goals of care. “Would I start this today?”

Rung 4

Prioritise & Choose One

Target the highest-risk, lowest-value drug first. Change one thing at a time so cause and effect stay clear.

Rung 5

Taper, Monitor, Support

Write a gradual taper, brief the patient on what to watch for, and follow up. Separate withdrawal from recurrence.

The Goal

Fewer, Better, Whole

The right list — not the empty list. Clarity, balance, and appetite return. The person is restored, not suppressed.

Deprescribing Protocols by Class

§ 19

The framework (§17) and ladder (§18) give the universal sequence. But the practical question — can this drug simply stop, or must it be tapered, and how fast? — depends on the class. The table below translates the general rule into class-specific posture. It is a teaching guide to the principle; every taper schedule must be set against current product information and local protocols.

Class	Stop or Taper?	Why — and What to Watch
Benzodiazepines / Z-drugs	Slow taper	Abrupt stop risks rebound anxiety, insomnia, and seizures. Reduce in small steps over weeks to months; hold if withdrawal appears rather than reversing.
Opioids	Slow taper	Abrupt stop causes a distressing withdrawal syndrome. Gradual reduction with support; pair with non-opioid strategies (see §21).
SSRIs / SNRIs	Taper	Abrupt stop causes a discontinuation syndrome (dizziness, “brain zaps,” flu-like symptoms) — a withdrawal effect, not relapse. Reduce gradually.
Proton-pump inhibitors	Step down / brief taper	Stopping suddenly after long use can cause rebound acid hypersecretion. Step down dose or frequency; many can then stop entirely.
Corticosteroids (chronic)	Mandatory taper	Abrupt stop after prolonged use risks adrenal crisis. Never stop suddenly; reduce per protocol.
Beta-blockers	Taper	Abrupt stop can cause rebound tachycardia, hypertension, or ischemia. Reduce gradually.
Gabapentinoids	Taper	Abrupt stop risks withdrawal including anxiety and, rarely, seizures. Reduce gradually.
Most antihypertensives / many others	Often stop or reduce directly	Many drugs can be reduced or stopped without a formal taper — but always monitor the condition the drug was treating for return.

The Cardinal Rule

When in doubt, go slower. There is rarely harm in tapering a drug more gradually than necessary; there is real harm in stopping a taper-requiring drug abruptly. “The taper is part of the prescription” (§20) applies to every class above marked taper.

Interactive Clinical Partner

Stop or Taper? Decision Helper

Select a class to see the recommended deprescribing posture, the risk of getting it wrong, and the monitoring focus. This illustrates principles only and never overrides a current product monograph or local protocol.

⚡

Select a class

Choose a medication class above to see whether it can be stopped directly or must be tapered, and why.

Monitoring focus appears here once a class is selected.

Tapering & the Withdrawal Trap

§ 20

Some drugs must be reduced gradually, never stopped at once: benzodiazepines, opioids, gabapentinoids, beta-blockers, corticosteroids, SSRIs and SNRIs, and proton-pump inhibitors among them. Abrupt cessation can cause rebound symptoms, autonomic instability, or harm in its own right. The taper is part of the prescription.

The Withdrawal Trap

When a drug is stopped and the patient feels worse, the reflex is to conclude “they still need it” and restart at full dose. But a transient withdrawal effect is not the same as recurrence of the original condition. Mistaking one for the other re-anchors the very drug you were trying to remove — and quietly teaches the team that deprescribing “does not work.”

Reduce in small, scheduled steps with a written plan
Change one medication at a time
Warn the patient which withdrawal effects are expected and time-limited
Give a clear point of contact and a safety net
Re-assess at each step before the next reduction
Document the rationale and the response

Don’t

Stop a taper-requiring drug abruptly
Reduce several drugs at once and lose the signal
Assume every symptom after stopping is recurrence
Restart at full dose at the first discomfort
Deprescribe in a crisis or unstable moment
Leave the patient without a plan or a phone number

A Steady Hand

Go slow. Half the dose, then half again. If a symptom appears, hold — do not automatically reverse. Most withdrawal effects fade within days to weeks. Patience at the taper is where deprescribing succeeds or fails.

Opioid Stewardship

§ 21

Opioids deserve a section of their own. They are genuinely valuable for acute pain and for compassionate care at the end of life — and they are simultaneously a high-alert class (§10) whose harms scale steeply with dose, duration, and combination. Stewardship is the same stewardship this whole module teaches: the right drug, at the lowest effective dose, for as long as it earns its place — and a plan to come off.

The Two Highest-Risk Patterns

Dose escalation — rising doses for tolerance or unaddressed pain, where benefit plateaus but respiratory and overdose risk keeps climbing. Dangerous combinations — opioids stacked with benzodiazepines, gabapentinoids, alcohol, or other sedatives, an additive pharmacodynamic effect (§06) that multiplies the risk of fatal respiratory depression. Screen every opioid regimen for overlapping sedatives.

Start

Lowest Effective, Shortest Course

Begin with the smallest dose for the shortest sensible duration, with an explicit plan for reassessment. An opioid started for acute pain should not silently become a standing medication.

Pair

Multimodal Pain Care

Combine with non-opioid analgesia and non-drug strategies so the opioid carries less of the load. Treating pain well is not the same as treating it with more opioid.

Screen

Check the Whole Regimen

Look for sedative co-prescriptions, organ impairment (§05) that slows clearance, and signs the dose has outgrown its benefit. The most dangerous opioid is the one combined unseen.

Plan

Taper, Don’t Drop

Long-term opioids require a gradual, supported taper (§19–20), never an abrupt stop. Co-prescribe overdose-reversal where indicated and brief the patient and family.

Compassion Is Not the Opposite of Caution

Stewardship is not under-treating pain, and it is not abandoning the patient who is already dependent. It is refusing the false choice between “more opioid” and “suffering.” In palliative and end-of-life care especially, the goal shifts to comfort and the same agents are used differently — deliberately, and without apology. Verify all dosing, combinations, and tapers against current local protocols.

Adherence: The List on Paper vs the List in the Body

§ 22

The chart says one thing; the bloodstream says another. Adherence — whether a person actually takes a medication as intended — is the hidden variable behind countless “treatment failures” and dangerous dose escalations. It connects directly to polypharmacy: the more drugs, the more complex the schedule, the lower the adherence, and the greater the chance of error in both directions — missed doses and accidental doubling.

The Escalation Trap

When a drug appears not to work, the reflex is to raise the dose or add another agent. But if the real problem is that the patient is not taking it — or is taking it incorrectly — escalation builds a hazard: the day they do take it as prescribed, they receive a dose calibrated for non-adherence. Always ask how a drug is being taken before concluding it has failed.

Cause

Complexity

Many drugs, many times a day, many rules (with food, on an empty stomach, not with the mineral). Complexity is the enemy of adherence — and a direct argument for deprescribing the unnecessary.

Cause

Side Effects & Beliefs

People quietly stop drugs that make them feel worse, or that they do not understand the reason for. A drug with no felt benefit and a real side effect is one a patient may abandon without telling anyone.

Cause

Cost & Access

Skipped refills and dose-stretching to save money are common and rarely volunteered. Ask about affordability plainly and without judgment.

Cause

Practical Barriers

Vision, dexterity, swallowing, memory, and child-resistant caps all defeat good intentions. The regimen must fit the person’s real capabilities.

Ask Without Blame

The way you ask determines the truth you get. “Are you taking your medications?” invites a defensive yes. Try instead: “Many people find it hard to take every dose — in the last week, which ones did you miss or skip?” Normalising imperfection surfaces the real pattern, and the real pattern is what lets you fix the regimen rather than inflate it.

Fewer Drugs, Better Adherence

Deprescribing and adherence reinforce each other. A shorter, simpler, side-effect-light list is one a person can actually follow — so the right medicines reach the body, and the wrong ones are gone. Simplifying the schedule is itself a clinical intervention.

Talking to the Prescriber: SBAR

§ 23

A nurse or pharmacist who suspects a drug is harming a patient is not overriding the prescriber — they are giving the prescriber data that cannot be seen from the order-entry screen. SBAR turns a worry into a clear, actionable clinical communication.

Situation

State it in one line. “Mr. A has become confused and unsteady over the past week.”

Background

Give the relevant context. “His oxybutynin and diphenhydramine were both started 10 days ago; ACB score is now 4.”

Assessment

Offer your read. “This looks like cumulative anticholinergic burden, not a new dementia.”

Recommendation

Propose the action. “Can we stop the diphenhydramine and review the oxybutynin?”

Document the Observation, Not the Verdict

Record what you actually saw — the timeline, the dose change, the specific symptom — and the temporal link between them. Concrete observations are what let a prescriber act. “Patient seems off” cannot be acted on; “new confusion three days after the dose increase” can.

Medication Safety Is a System, Not a Hero

§ 24

Every cascade and adverse event in this module shares a root cause: a system that lets harm slip through, not a single careless person. The composite failures in §26 happen because each clinician sees only their own prescription and no one sees the sum. The remedy is therefore architectural — build the safeguards into the system so safety does not depend on any one person catching everything.

Blame the Process, Not the Person

A culture that punishes the individual who makes an error teaches everyone to hide errors — and hidden errors cannot be fixed. A just culture separates honest mistakes within a flawed system from genuine recklessness, and treats most events as information about the process. You cannot improve what people are afraid to report. This is the same root-cause discipline WestNet applies everywhere: fix the system that allowed it.

See the Sum

One Shared List

The deepest safeguard is a single, reconciled medication list visible to every prescriber, pharmacist, and nurse across settings — so the drug no one was watching becomes the drug everyone can see. This is the core premise of a unified platform.

Decision Support

Alerts That Help

Interaction, duplicate, dose, and allergy checks at the point of prescribing catch errors before they reach the patient — if they are tuned to flag what matters. Poorly tuned alerts cause “alert fatigue,” and a numbed clinician clicks past the warning that counted.

Independent Check

Double-Check High-Alert

For high-alert drugs (§10), a true independent second check — not a glance — catches errors a single person cannot see in their own work. Build it into the workflow for the agents that matter most.

Standardise

Reduce the Chances to Err

Standard order sets, clear labelling, look-alike/sound-alike separation, and removal of dangerous abbreviations make the safe action the easy action — engineering error out rather than exhorting people to try harder.

The Five Rights — and Their Limits

The classic checks — right patient, drug, dose, route, time — remain a useful bedside discipline. But they are goals, not a system: telling a rushed, interrupted clinician to “just be careful” is not a safeguard. Real safety pairs the Five Rights with system design that makes the wrong action hard in the first place.

Where the Clinician Fits

Systems do not replace the disciplined individual — they support one. The nurse or pharmacist who asks “is the drug causing this?”, reconciles honestly, and raises a concern via SBAR (§23) is the human safeguard the system is built around. Report near-misses so the architecture keeps improving; the next error you prevent may be one you never see.

Reframe the Reflex

§ 25

Deprescribing fails not for lack of evidence but for lack of language. The phrases that come most naturally — to staff, to patients, to ourselves — quietly defend the status quo. Tap any card to flip the reflexive thought into the stewardship reframe, and see why it changes the decision.

Why Framing Matters

“Don’t rock the boat” sounds like caution but is often inertia wearing caution’s clothes. Re-asking “would I start this today?” for every drug, every visit, is how a regimen stays honest — and how the person, not the list, stays at the centre of care.

When Safeguards Fail: A Composite Pattern

§ 26

The following pattern recurs across North American medication use. It is a composite case drawn from systemic failures — not any single patient, prescriber, or institution. The lesson is architectural, not personal.

Pattern: The Regimen That Built Itself

An older adult, independent and sharp, is started on a bladder drug for urgency. Within weeks they are forgetful; a cognitive workup is ordered and a dementia drug begun. The dementia drug causes loose stools; a constipating agent is added. Sedation appears; the “dementia” is judged to be progressing and an antipsychotic is started. Each step was documented, defensible, and well-intentioned. No one ever asked whether the first drug caused the confusion that started it all.

What Module 06 Teaches

Every safeguard in the chain fails when each clinician sees only their own prescription and never the sum. At Rung 2 of the deprescribing ladder — is a drug the cause? — this entire cascade ends, and a person is handed back their clarity. The cheapest, safest, most humane intervention was a single question asked at the very first link.

Red Flags — Escalate Now

•Any new symptom appearing shortly after a new or increased drug — treat the medication as the suspect until proven otherwise.
•One or more falls in a person on sedatives, antihypertensives, or anticholinergics.
•High anticholinergic burden together with new or worsening cognitive decline.
•Abrupt stop of a benzodiazepine, opioid, or antidepressant — high withdrawal risk; these require a planned taper, never a sudden halt.
•One or more Beers / STOPP high-risk medicines on an older adult's list.

Action: review and deprescribe — fewer, right medicines.

Putting It Together: Self-Check

§ 27

This section weaves the threads of the module into a single self-check. Each scenario draws on more than one earlier idea — pharmacokinetics, the cascade, anticholinergic burden, deprescribing, and safety systems — because real patients never present one concept at a time. Answer each item to see the reasoning. This is formative practice; the graded competency assessment follows in §29.

Interactive Comprehensive Check

Scenario Self-Check

Five integrated scenarios. Choose the best response to reveal immediate feedback and the principle behind it. Your running score appears below — it is for your own reflection only.

0/5

Begin the self-check

Answer the scenarios above to build your score and review the reasoning.

A self-check is a mirror, not a gate. Wherever a scenario surprised you, revisit the linked section — and remember the unifying question: is the drug causing this?

The One Question

If a single habit survives this module, let it be this: in any person on more than one medication, when something new appears, ask first — could a drug be causing this? — before reaching for the next prescription. Everything else here is the discipline that makes that question answerable.

References & Evidence Base

§ 28

The clinical positions in this module draw on peer-reviewed literature indexed by the U.S. National Library of Medicine (PubMed / PMC) and on the published criteria of major clinical-guideline bodies. Each citation below links to its source — journal articles open a PubMed search for the title; library and guideline bodies link to their official site.

By the 2023 American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society. 2023.Search via PubMed (U.S. National Library of Medicine)
O’Mahony D, et al. STOPP/START criteria for potentially inappropriate prescribing in older people: version 2. Age and Ageing. 2015.Search via PubMed (U.S. National Library of Medicine)
Scott IA, et al. Reducing inappropriate polypharmacy: the process of deprescribing. JAMA Internal Medicine. 2015.Search via PubMed (U.S. National Library of Medicine)
Rochon PA, Gurwitz JH. Optimising drug treatment for elderly people: the prescribing cascade. BMJ. 1997.Search via PubMed (U.S. National Library of Medicine)
U.S. National Library of Medicine, MedlinePlus. Polypharmacy / Managing Your Medicines. MedlinePlus — medlineplus.govU.S. National Library of Medicine consumer health resource
National Center for Complementary and Integrative Health (NIH). Herb–Drug Interactions and the Safety of Dietary Supplements. NCCIH — nccih.nih.govU.S. National Institutes of Health
Reeve E, et al. A systematic review of the emerging definition of ‘deprescribing’ with network analysis: implications for future research and clinical practice. British Journal of Clinical Pharmacology. 2015.Search via PubMed (U.S. National Library of Medicine)
Mangoni AA, Jackson SHD. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2004.Search via PubMed (U.S. National Library of Medicine)
Institute for Safe Medication Practices (ISMP). ISMP List of High-Alert Medications in Acute Care Settings. ISMP — ismp.orgInstitute for Safe Medication Practices
Dowell D, Ragan KR, Jones CM, Baldwin GT, Chou R. CDC Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. MMWR Recommendations and Reports. 2022.Search via PubMed (U.S. National Library of Medicine)
World Health Organization. Medication Without Harm — WHO Global Patient Safety Challenge. WHO — who.intWorld Health Organization

Evidence Note

Drug examples in this module are illustrative and composite. This reference list is a starting point for further reading — it does not replace facility formulary policy, current product monographs, or jurisdictional scope-of-practice guidance.

Competency Assessment

§ 29

Fifteen questions. Pass threshold: 11/15 for CE credit (upon accreditation approval).

Define inappropriate polypharmacy. Why is a raw medication count alone an inadequate measure?

Describe the prescribing cascade and give one concrete example of a chain of three drugs.

List the three steps of medication reconciliation and name two sources for a Best Possible Medication History.

What is the Beers Criteria, and what does it mean when a drug appears on it — is the drug forbidden?

What is anticholinergic burden, why is it cumulative, and what ACB total signals meaningful risk?

A patient becomes confused one week after a dose increase. State the disciplined first question to ask.

Name the six steps of the deprescribing framework in order.

Distinguish a withdrawal effect from disease recurrence. Why does confusing them entrench the drug?

Use SBAR to raise a concern that a patient’s diphenhydramine is contributing to confusion.

Q10

Explain how “fewer-but-right medicines” can restore a person rather than simply doing less.

Q11

Distinguish pharmacokinetics from pharmacodynamics. Using half-life, explain why a drug’s harm can persist for days after the last dose.

Q12

Why can a “normal” serum creatinine still hide poor kidney function, and what is the safety consequence for a renally-cleared, narrow-index drug?

Q13

Contrast CYP450 inhibition with induction: what happens to the affected drug’s level in each, and roughly how fast?

Q14

What makes a medication “high-alert,” and why is an independent double-check a reasonable safeguard for this group?

Q15

Name the two highest-risk opioid patterns, and explain why suspected non-adherence should be checked before a dose is escalated.

Accreditation & Faculty

§ 30

Accreditor	Status
ANCC (American Nurses Credentialing Center)	Application pending
ACCME (Accreditation Council for Continuing Medical Education)	Application pending
CARNA (College of Registered Nurses of Alberta)	Application pending
CPSA (College of Physicians & Surgeons of Alberta)	Planned

Course Director: WestNet Medical Clinical Education Division
Publication: WestNet Medical Publications • WestNet Catalog 731985456611 • ISBN 978-0-XXXXX-XXX-X (Pending)
Platform: WestNet Unified Health Platform / HealthOS v3.6

Glossary

Ref

ACB scale	Anticholinergic Cognitive Burden scale. Scores each anticholinergic drug 1–3 and sums them; a total ≥ 3 signals meaningful cognitive and falls risk.
Anticholinergic burden	The cumulative anticholinergic effect of all of a person’s medications combined. Individually mild drugs can add up to marked harm.
Beers Criteria	American Geriatrics Society list of potentially inappropriate medications in older adults — a prompt to justify, not a ban.
Best Possible Medication History (BPMH)	A verified medication history built from two or more sources, including the patient, pharmacy records, and the bottles themselves.
Deprescribing	The planned, supervised reduction or cessation of medications that may be harmful or no longer beneficial, to improve outcomes. An active clinical intervention.
HealthOS	WestNet’s unified clinical platform spanning ER, inpatient, pharmacy, labs, and primary care across Canada and the USA — surfacing every active medication across prescribers.
Iatrogenic	Harm caused by medical treatment itself — including adverse drug effects and medication-induced symptoms.
Medication reconciliation	The structured process of collecting, comparing, and reconciling a patient’s medications at each transition of care.
Polypharmacy	Concurrent use of multiple medications, commonly five or more. Inappropriate polypharmacy — not the count itself — is the clinical concern.
Prescribing cascade	When an adverse drug effect is misread as a new condition and treated with another drug, which causes its own effect, and so on.
SBAR	Situation, Background, Assessment, Recommendation — a structured format for communicating a medication concern to a prescriber.
STOPP/START	European criteria pairing drugs to consider stopping (STOPP) with beneficial treatments often wrongly omitted (START).
Taper	A planned, gradual dose reduction used for drugs that cannot be stopped abruptly, to avoid withdrawal or rebound.

Related WestNet Medical Modules

This module is part of a 12-title series. See also: Module 07 — Iatrogenic Harm & De-escalation, Module 10 — Diabetes & Endocrine, Module 11 — Elder Care & Delirium, and Module 03 — Nutrition.

Polypharmacy & DrugInteraction Management

Continuing Education Information

Program Preface

The Reflex: Add, Never Subtract

The Four Pillars of WestNet Medication Stewardship

Reconcile Completely

Ask If The Drug Is The Cause

Subtract With Skill

Restore The Person

How Drugs Move & Act: PK & PD Basics

Absorption

Distribution

Metabolism

Elimination

Renal & Hepatic Dosing Principles

Estimate, Don’t Assume

Know the Renally-Cleared

Respect the First-Pass Liver

Re-check When Status Changes

How Interactions Happen: CYP450 & Mechanisms

CYP450 Inhibition

CYP450 Induction

Binding / Chelation

Transporter & Renal Competition

Additive / Synergistic Effect

Antagonism

Medication Reconciliation Across Transitions

Collect (Best Possible History)

Compare

Reconcile & Communicate

Indication For Every Drug

Ask Widely, Without Judgment

Verify Against the Bottles

What Not to Say

Recognising an Adverse Drug Event

Timing

Plausibility

Dechallenge

Alternatives

High-Risk Classes & the Beers Criteria

High-Alert Medications

Drug-Class Deep Dives

Benzodiazepines & Z-Drugs

Proton-Pump Inhibitors (PPIs)

NSAIDs

Antipsychotics (for behaviour in dementia)

Cardiovascular & Glucose-Lowering Agents

Anticholinergic Burden — The Hidden Sum

Anticholinergic Burden in Depth

The Prescribing Cascade

Cascade Explorer — Walk the Chain, Find the Off-Ramp

Herb & Supplement Interactions

The Deprescribing Framework

Compile the Full List

Review Each Indication

Weigh Current Risk vs Benefit

Prioritise What to Stop

Plan the Taper

Monitor & Support

The WestNet Deprescribing Ladder

Deprescribing Protocols by Class

Tapering & the Withdrawal Trap

Opioid Stewardship

Lowest Effective, Shortest Course

Multimodal Pain Care

Check the Whole Regimen

Taper, Don’t Drop

Adherence: The List on Paper vs the List in the Body

Complexity

Side Effects & Beliefs

Cost & Access

Practical Barriers

Talking to the Prescriber: SBAR

Situation

Background

Assessment

Recommendation

Medication Safety Is a System, Not a Hero

One Shared List

Alerts That Help

Polypharmacy & Drug
Interaction Management