Medication Error (ME) — Definition

"Any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the health care professional, patient, or consumer."

Types of Medication Errors (with examples)

1. Prescribing Error Wrong drug, dose, route, or frequency chosen, or a drug prescribed despite a known allergy/interaction. Example: Prescribing amoxicillin to a patient with a documented penicillin allergy.
2. Transcription Error Error made when transferring an order from one document/system to another (e.g., paper to electronic chart). Example: "5 mg" misread/copied as "50 mg."
3. Dispensing Error Pharmacy issues the wrong drug, strength, or formulation, often due to look-alike/sound-alike (LASA) names. Example: Dispensing hydroxyzine instead of hydralazine.
4. Administration Error Error at the point of giving the drug to the patient - wrong patient, wrong time, wrong route, or wrong technique. Example: Giving an IV-only medication intrathecally, or giving a drug to the wrong patient.
5. Monitoring Error Failure to review a prescribed regimen for appropriateness, or to monitor for therapeutic response/toxicity. Example: Not checking INR levels in a patient on warfarin, leading to bleeding.
6. Documentation Error Incorrect or missing recording of medication given (or omitted), causing confusion in the chart. Example: Nurse forgets to chart an administered dose, leading to a duplicate dose being given later.
7. Compliance/Deterioration Error (Patient-related) Errors from patient non-adherence or improper storage/use at home. Example: Patient doubles insulin dose after missing a scheduled dose.

Common Underlying Causes

• Illegible handwriting or unclear abbreviations
• Look-alike/sound-alike drug names or packaging
• Interruptions during preparation/administration
• Lack of double-checking (especially with high-alert drugs like insulin, heparin, opioids)