Patient Safety Case Study: When the Wrong Drug Is Dispensed
Analyze a real-world scenario where a look-alike medication error reached a patient. Learn root cause analysis and prevention strategies for pharmacy technicians.
The Scenario
A 72-year-old patient presented a new prescription for hydroxyzine 25mg for anxiety. The pharmacy technician pulled hydralazine 25mg from the shelf and filled the prescription. Both medications were stored in adjacent bins with similar-looking labels. The pharmacist, during a busy period with multiple prescriptions waiting, verified the prescription without catching the error. The patient took the wrong medication for three days before experiencing severe dizziness and hypotension, leading to an emergency room visit.
Root Cause Analysis
Several factors contributed to this error:
- Look-alike drug names - Hydroxyzine and hydralazine sound similar and are often stored near each other alphabetically
- Similar packaging - Both came from the same manufacturer in similar-sized bottles
- Workflow pressure - High prescription volume reduced time for careful verification
- Barcode bypass - The pharmacy's barcode scanning system was down, and manual verification was substituted
- Inadequate separation - The two drugs were stored in adjacent bins
What Should Have Happened
Multiple safeguards could have prevented this error:
- Tall man lettering on shelf labels: hydrOXYzine vs hydrALAzine
- Physical separation of LASA drug pairs on the shelf
- Barcode scanning at the point of filling, with no bypass allowed
- The technician visually comparing the NDC number on the stock bottle to the prescription label
- The pharmacist performing an independent check rather than relying on the technician's selection
Lessons for Technicians
Always read the full drug name, not just the first few letters. Verify the NDC number against the prescription. If the barcode scanner is down, slow down and double-check every selection manually. If something does not feel right, ask the pharmacist before proceeding.
Reporting the Error
This event should be reported internally through the pharmacy's error reporting system and externally through ISMP's Medication Error Reporting Program. Reporting helps identify system failures and drives improvements that protect future patients.
Case studies like this appear in PTCE patient safety questions. Practice identifying the root cause and the best prevention strategy.
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