PEBC MCQ study guide: Medication Safety & ISMP Canada Error Prevention

Providing Care – Distribution

LASA drugs, Tallman lettering, high-alert medications, and incident reporting/disclosure.

Look-Alike Sound-Alike (LASA) Drugs & Tallman Lettering

LASA pairs are a leading cause of dispensing errors — classic exam pairs include hydrALAzine/hydrOXYzine, DOBUTamine/DOPamine, predniSONE/prednisoLONE, clonazePAM/cloNIDine/clomiPRAMINE, and traMADol/traZODone. Tallman lettering (capitalizing the distinguishing letters, as shown above) is an ISMP Canada-endorsed strategy used on shelf labels and in computer systems to visually break the similarity and draw attention to the differentiating letters.

System-level mitigations beyond Tallman lettering: physically separating LASA products on the shelf (not storing them alphabetically-adjacent by default), including the indication on prescriptions/labels where feasible (helps catch a wrong-drug selection that "looks right" alphabetically but doesn't match the stated indication), and independent double-checks for high-alert medications specifically.

High-Alert Medications

High-alert medications are drugs that carry a heightened risk of causing significant patient harm when used in error — not necessarily because errors are more common with them, but because the CONSEQUENCE of an error is disproportionately severe. Classic high-alert classes: insulin, opioids, anticoagulants/heparin, concentrated electrolytes (potassium chloride injection, hypertonic saline), chemotherapy agents, and neuromuscular blocking agents. These warrant independent double-checks (two separate clinicians independently verifying the calculation/product/rate before administration, not one person checking their own work) and, in hospital settings, are frequently stored separately from general stock with additional access controls (e.g., concentrated potassium chloride is not typically kept in general ward stock at all).

Root Cause Analysis, Incident Reporting & Disclosure

Root Cause Analysis (RCA) investigates a medication incident by asking "why" iteratively to identify underlying SYSTEM failures (e.g., look-alike packaging, inadequate staffing, workflow interruption, alert fatigue) rather than stopping at "who made the error" — modern patient-safety culture treats most errors as a symptom of a system gap, not simply individual fault, though this does not eliminate individual accountability for reckless or repeated disregard of safety protocols.

Disclosure: patients have a right to be informed when a medication error has affected their care, regardless of whether harm occurred — many provinces and hospital policies mandate open disclosure as both an ethical and, increasingly, a regulatory/legal obligation. Reporting an incident (even a "near miss" that was caught before reaching the patient) to an internal or provincial incident-reporting system is distinct from disclosure to the patient — both matter, and near-miss reporting specifically is valuable because it identifies system vulnerabilities before they cause actual harm.

High-yield points

Tallman lettering (hydrALAzine/hydrOXYzine) is an ISMP Canada-endorsed visual strategy to reduce LASA errors — paired with physical shelf separation.
High-alert meds (insulin, opioids, anticoagulants, concentrated electrolytes, chemo) need independent double-checks because the CONSEQUENCE of error is severe, not necessarily because errors are more frequent.
RCA asks "why" iteratively to find system failures, not just individual fault — but this doesn't remove accountability for reckless behaviour.
Patients have a right to disclosure of a medication error affecting their care, regardless of whether actual harm occurred; near-miss internal reporting is separate from — and just as important as — patient disclosure.

Guideline references

ISMP Canada — List of Look-Alike Sound-Alike Drug Names
ISMP Canada — Tallman Lettering Guidance
Canadian Patient Safety Institute