Dispensing & Medication Errors

Dispensing is one of the most safety-critical functions performed by pharmacists and pharmacy technicians. Every step in the dispensing workflow carries risk, and a systematic approach is essential to minimising harm to patients. This lesson covers the full dispensing workflow, the hazards posed by look-alike/sound-alike (LASA) drugs, the five rights framework, near-miss reporting systems, landmark New Zealand Health and Disability Commissioner (HDC) cases, and root cause analysis (RCA) methodologies.

The Dispensing Workflow

The standard dispensing workflow in New Zealand community and hospital pharmacies comprises the following sequential stages:

1. Prescription Receipt and Initial Screening

When a prescription arrives — whether paper, fax, or electronic (ePrescription via the NZ Health Sector PKI infrastructure) — the dispensary staff perform an initial legibility and completeness check. Mandatory prescription elements under the Medicines Regulations 1984 include: patient full name and date of birth, prescriber name, registration number, and signature, date of issue, approved name of medicine, dose, frequency, quantity, and route of administration. Any prescription lacking these elements must be queried before dispensing proceeds.

2. Clinical Screening by the Pharmacist

The pharmacist reviews the prescription against the patient medication record (PMR). This clinical check encompasses therapeutic appropriateness (correct drug for condition), dose range verification against age and renal/hepatic function, drug–drug interaction screening, allergy and contraindication review, and duplication of therapy detection. In New Zealand, pharmacists have legal authority under the Medicines Act 1981 to decline to dispense a prescription they believe may harm the patient, and are obligated to document this decision.

3. Data Entry

A trained dispensary technician (or the pharmacist) enters the prescription into the dispensary software (commonly Toniq, Fred Dispense, or Lots in NZ). Accurate entry of drug name, strength, quantity, and directions is critical. Barcode scanning of dispensary stock against the entry reduces transcription error risk.

4. Label Generation and Printing

Labels must comply with the Medicines Regulations 1984: patient name, drug name and strength, directions for use, dispensary name and address, date, prescriber name, expiry where relevant. Warnings and advisory labels (e.g., "Take with food", "Avoid alcohol") are generated automatically by dispensary software.

5. Product Selection and Picking

The correct product is retrieved from stock. This step is where LASA errors most commonly occur. Many pharmacies use tall-man lettering on shelf labels and separate storage of LASA pairs to reduce risk.

6. Accuracy Check

The final dispensed product is checked — either by a second pharmacist or by a pharmacist checking their own work — against the original prescription, the label, and the product. This includes checking drug name, strength, quantity, expiry date, and integrity of packaging.

7. Patient Counselling and Handover

The pharmacist or trained staff provide appropriate counselling at the point of handover (see Lesson 4). Written information may be provided. Dose administration aids (DAAs) are prepared where prescribed.

8. Documentation and Record-Keeping

The completed dispensing event is recorded in the PMR. For controlled drugs (Schedule 1-4), entries must also be made in the controlled drug register as required under the Misuse of Drugs Regulations 1977.

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Look-Alike / Sound-Alike (LASA) Drugs

Look-alike/sound-alike (LASA) drugs are medications whose names or packaging closely resemble those of other products. LASA confusion is a leading cause of dispensing error worldwide and is consistently implicated in New Zealand HDC cases.

Common LASA Pairs in NZ Practice

| Drug A | Drug B | Confusion Type | Risk |

|--------|--------|---------------|------|

| Glipizide | Glibenclamide | Sound-alike | Hypoglycaemia |

| Metformin | Methotrexate | Look-alike | Toxicity |

| Hydroxyzine | Hydralazine | Sound-alike | Sedation/hypotension |

| Carbamazepine | Carbimazole | Look-alike | Agranulocytosis |

| Lamivudine | Lamotrigine | Look-alike | Seizure |

| Cyclophosphamide | Cyclosporine | Look-alike | Immunosuppression |

| Novolog (insulin aspart) | Novolin (insulin regular) | Look-alike | Hypo/hyperglycaemia |

| Prednisolone | Prednisone | Similar | Dose conversion error |

Mitigation Strategies

The Institute for Safe Medication Practices (ISMP) recommends a hierarchy of controls:

• *Eliminate*: Remove one product from formulary where possible.
• *Separate*: Store LASA pairs in different physical locations; do not alphabetise them adjacently.
• *Differentiate*: Use tall-man (mixed-case) lettering (e.g., DOPamine vs DOBUTamine) on labels and shelf signs.
• *Alert*: Use software-generated LASA alerts at data entry; bright stickers or auxiliary labels on stock.
• *Barcode scanning*: Point-of-dispense barcode verification significantly reduces picking errors.

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The Five Rights of Medication Safety

The "five rights" framework provides a minimum checklist for safe medication administration and dispensing:

1. Right Patient — Verify full name and date of birth (two patient identifiers). In hospitals, use wristband and NHI number.
2. Right Drug — Confirm approved name, brand, strength. Check LASA alerts.
3. Right Dose — Verify dose is within therapeutic range for patient-specific factors (age, weight, renal function).
4. Right Route — Confirm route is appropriate; ensure correct formulation (oral, IV, topical, etc.).
5. Right Time — Correct frequency and timing; note interactions with food, other drugs, chronotherapy.

Extended frameworks add:

• Right Documentation — Record that the dose was given/dispensed.
• Right Reason — The drug is indicated for the patient's confirmed diagnosis.
• Right Response — Monitor and document therapeutic outcome and adverse effects.

In New Zealand hospital practice, the five rights are embedded in Medication Management policies mandated by Health New Zealand (Te Whatu Ora) district standards.

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Near-Miss Reporting

A near-miss (or "close call") is an error that was caught before it reached the patient. Near-misses are invaluable learning opportunities — for every serious adverse medication event, there are estimated to be 100–300 near-misses at preceding stages (the "safety pyramid" or Heinrich's triangle adapted for healthcare).

Reporting Systems in NZ

• *In-practice incident forms*: Pharmacy-specific paper or electronic forms completed by the staff member who identified the near-miss.
• *CARM (Centre for Adverse Reactions Monitoring)*: Accepts voluntary reports of adverse drug reactions and medication errors; based at the University of Otago.
• *Health Quality & Safety Commission (HQSC)*: National adverse events reporting; mandatory for sentinel events.
• *Medsafe*: Receives product quality defect and labelling issue reports.

Barriers to Reporting

Fear of blame and punitive consequences is the most commonly cited barrier. Psychological safety — a culture where staff feel safe to raise concerns without fear of retribution — is essential for effective reporting. The just culture model (advocated by the HQSC) distinguishes between human error (supportive response), at-risk behaviour (coaching), and reckless behaviour (disciplinary).

Using Near-Miss Data

Near-miss reports should be aggregated, de-identified, and reviewed regularly at team meetings. Trend analysis reveals systemic vulnerabilities that can be addressed before a patient is harmed.

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NZ Health and Disability Commissioner Cases

The Health and Disability Commissioner (HDC) investigates complaints about health and disability services in New Zealand under the Health and Disability Commissioner Act 1994 and the Code of Health and Disability Services Consumers' Rights. Landmark pharmacy-related cases include:

Case 11HDC01456 (Community Pharmacy)

A community pharmacist dispensed methotrexate weekly as prescribed, but when the GP changed the dose on a repeat prescription the pharmacist dispensed the new dose daily, resulting in methotrexate toxicity. The HDC found a breach of Right 4(1) (appropriate standard of care). Outcome: mandatory education, practice review, and revised protocols for high-alert medicines.

Case 14HDC01278

A dispensing technician dispensed carbamazepine 400 mg instead of carbimazole 40 mg for a patient with hyperthyroidism. The error was not identified at the pharmacist accuracy check. The patient developed agranulocytosis. HDC found breaches by both the technician and the supervising pharmacist. The pharmacy implemented mandatory double-checks for all LASA drug pairs.

Case 16HDC00932 (Hospital Pharmacy)

An inpatient received IV potassium chloride undiluted due to a labelling error — a concentrated electrolyte (potassium 40 mmol in 20 mL) was not segregated from normal saline flush syringes. The HDC case highlighted the need for concentrated electrolyte storage controls. Health NZ subsequently mandated removal of concentrated potassium chloride from ward stock.

These cases consistently identify common root causes: inadequate verification steps, failure to query unusual prescriptions, over-reliance on individual vigilance rather than systemic safeguards, and poor communication between prescriber and pharmacist.

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Root Cause Analysis (RCA)

Root cause analysis is a structured investigation methodology used after a significant adverse event or near-miss. Its goal is to identify the underlying systemic and process causes — not to assign blame.

RCA Process Steps

1. *Immediate response*: Ensure patient safety; preserve evidence (retain the dispensed product, original prescription, computer entry records, CCTV where available).
2. *Team assembly*: Multi-disciplinary team including pharmacy staff, clinical staff, risk manager, patient advocate (where appropriate).
3. *Timeline construction*: Detailed chronological event reconstruction.
4. *Causal factor identification*: Use the "5 Whys" technique — repeatedly ask "why did this happen?" until the root cause(s) are reached.
5. *Fishbone (Ishikawa) diagram*: Organise causes across categories: People, Process, Equipment, Environment, Materials, Management.
6. *Recommendations and actions*: SMART (Specific, Measurable, Achievable, Relevant, Time-bound) recommendations with named owners and deadlines.
7. *Follow-up audit*: Verify that implemented changes achieved the desired risk reduction.

Hierarchy of Controls Applied to Dispensing

• *Forcing functions* (highest): Software hard-stops that prevent dispensing without two-ID patient verification.
• *Physical barriers*: Segregated LASA storage, locked high-alert medicine cupboards.
• *Reminders/checklists*: LASA stickers, high-alert medicine protocols.
• *Training and education* (lowest): Important but insufficient as the sole control.

The HQSC's Medication Safety Programme and the NZ Pharmacy Council's competency standards both mandate that pharmacists be competent in identifying, reporting, and learning from medication errors using RCA principles.