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Methotrexate intoxication: the Pharmaceutical Care process reveals a critical error.
I Arnet1, V Bernhardt, K E Hersberger
1Pharmaceutical Care Research Group, University of Basel, Switzerland. isabelle.arnet@unibas.ch
Journal of Clinical Pharmacy and Therapeutics
|April 6, 2011
Summary
Community pharmacists detected accidental low-dose methotrexate (MTX) intoxication in a patient due to incorrect daily instead of weekly dosing. This highlights the critical role of pharmaceutical care in preventing medication errors and ensuring patient safety.
Area of Science:
- Pharmacology
- Patient Safety
- Clinical Pharmacy
Background:
- Oral low-dose methotrexate (MTX) intoxication is a frequent issue, often stemming from medication dosing errors.
- Incorrect dosing frequency, particularly daily instead of weekly intake, is a common cause of accidental MTX toxicity.
Observation:
- A community pharmacist identified a case of MTX intoxication during routine Pharmaceutical Care using the SOAP (Subjective, Objective, Assessment, Plan) method.
- The patient, a 78-year-old widow, was taking MTX daily for oral mucositis instead of weekly, due to misinterpretation of written instructions.
Findings:
- The pharmacist's intervention, utilizing the SOAP method, uncovered the critical dosing error that led to the patient's hospitalization.
- The patient continued the incorrect dosage due to a strong belief in her adherence, despite adverse effects.
Implications:
- Routine pharmaceutical care by community pharmacists is crucial for detecting and preventing medication errors like MTX intoxication.
- Clear patient counseling, verification of understanding, and interprofessional communication are essential to mitigate risks associated with low-dose MTX therapy.
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