Look-Alike Error (Option A)
This is a classic look-alike medication error, where Hydralazine (an antihypertensive vasodilator) was confused with Hydroxyzine (an antihistamine) due to their visually similar drug names. 1
Understanding the Error Type
This scenario represents a look-alike drug name confusion error, which is one of the most common types of medication errors in clinical practice:
- Look-alike errors occur when drug names appear visually similar when written or displayed, leading to selection of the wrong medication 1, 2
- The Hydralazine/Hydroxyzine pair is specifically documented as a high-risk look-alike drug name combination that causes real-world errors in pharmacy chains 1
- Up to 25% of all medication errors are attributed to name confusion, with look-alike names being a primary contributor 2
Why This Is NOT the Other Options
Sound-alike error (Option B): While Hydralazine and Hydroxyzine do sound somewhat similar when spoken, this scenario describes a patient who "took" the wrong medication, suggesting they selected it themselves (likely reading a label or prescription) rather than receiving it based on verbal communication 1, 2
Handwriting error (Option D): This would require illegible handwriting by the prescriber that led to misinterpretation. The question states the provider "prescribed" Hydralazine 25mg without indicating poor handwriting was involved 3
Illegal prescription (Option C): Neither medication represents an illegal prescription - both are legitimate medications that can be legally prescribed 3
Clinical Significance
- Laboratory-based tests of visual perception and memory for drug name pairs like Hydroxyzine/Hydralazine significantly predict real-world error rates, with these tests explaining 37-45% of variance in actual pharmacy errors 1
- This specific drug pair has been validated as causing confusion in multiple large pharmacy chains 1
- The clinical consequences are significant: the patient received an antihistamine (which may cause sedation) instead of needed antihypertensive therapy 3
Prevention Strategies
Healthcare systems should implement safeguards to prevent look-alike errors 3, 2:
- Use of Tall Man lettering (hydrALAzine vs hydrOXYzine) to distinguish similar names 2
- Bar-coded medication administration systems that can reduce medication errors by at least 50% 3
- Pharmacist verification of prescriptions, as pharmacists obtain better medication histories than physicians and reduce error rates 3
- Patient education to recognize their medications by appearance and indication 3, 4