Related Experiment Video

Updated: Jun 3, 2026

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment
04:48

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment

Published on: January 7, 2015

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
PubMed
Abstract

Insights

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.

More Related Videos

Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses11:17

Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses

Published on: August 30, 2018

Multi-Gene Single Nucleotide Polymorphism Detection in Gastric Cancer Based on Ion Semiconductor Sequencing Platform06:21

Multi-Gene Single Nucleotide Polymorphism Detection in Gastric Cancer Based on Ion Semiconductor Sequencing Platform

Published on: May 10, 2024

Related Concept Videos

Pharmaceutical Poisoning: Potential Scenarios01:26

Pharmaceutical Poisoning: Potential Scenarios

Pharmaceutical poisoning can occur through various channels, impacting an estimated 2 million hospitalized patients in the U.S. annually with serious adverse drug responses. These scenarios encompass both therapeutic uses, such as drug toxicity, where even standard dosages can lead to severe central nervous system depression, and non-therapeutic exposures, including accidental ingestion by children, and environmental and occupational exposures.Unintentional poisonings often involve exploratory...
Pharmaceutical Poisoning: Treatment Strategies01:26

Pharmaceutical Poisoning: Treatment Strategies

Treatment strategies for poisoning are a critical aspect of emergency medicine, focusing on preventing the absorption of toxins and enhancing their elimination. When a poisoning incident occurs, the first response is to halt exposure and decontaminate the patient, particularly through gastrointestinal (GI) methods if the poison was ingested.Gastrointestinal Decontamination Techniques:Activated charcoal is the cornerstone of GI decontamination. It works through adsorption, binding the toxin to...
Therapeutic Drug Monitoring: Affecting Factors01:29

Therapeutic Drug Monitoring: Affecting Factors

Therapeutic Drug Monitoring (TDM) is the clinical practice of measuring specific drug levels in a patient's blood or body tissues to manage and optimize therapy. TDM is crucial for drugs with narrow therapeutic windows, like warfarin and phenytoin, where incorrect doses can lead to treatment failure or severe side effects. This monitoring ensures the dosage administered is within a safe and effective range. The factors affecting therapeutic drug monitoring include:Patient-Specific Factors:a.
Drug Toxicity: Dose-Dependent Reactions01:24

Drug Toxicity: Dose-Dependent Reactions

Drug toxicities can be stratified into pharmacological, pathological, or genotoxic based on their mechanisms. The incidence and severity of these toxicities generally increase with the drug's concentration in the body and exposure time.Pharmacological toxicity is evident when the therapeutic effects of drugs overshoot into adverse reactions in a predictable, dose-dependent manner. Central nervous system (CNS) depression from barbiturates is a classic example, with effects escalating from...
Drug toxicity: Drug–Drug Interaction01:30

Drug toxicity: Drug–Drug Interaction

Drug–drug interactions can precipitate toxicity through multiple mechanisms. Absorption interactions alter how drugs enter the body, exemplified when ranitidine increases the absorption of basic drugs, while cholestyramine decreases the levels of propranolol. Protein binding interactions occur when drugs share the same binding sites on plasma proteins. Drugs like aspirin and warfarin, when bound in excess, can lead to increased free drug concentrations, enhancing the potential for...
Drug Toxicity: Overview01:00

Drug Toxicity: Overview

Drug toxicity quantifies the harm a compound causes to an organism, varying by dose and potentially impacting whole systems or specific organs like the liver. Toxic reactions may arise from venomous insect or spider bites, with effects ranging from mild symptoms to severe outcomes such as brain damage or death. Common forms of acute poisoning include ethanol intoxication and overdose of pain or fever medications, with substances like GHB and heroin being particularly lethal at doses close to...