Understanding Patient Safety: What is considered a high risk medication?

October 11, 2025 •

4 min read

Adverse drug events (ADEs) are projected to be the third leading cause of death in the United States, accounting for over 250,000 deaths annually [1.6.6]. A key part of this issue involves understanding what is considered a high risk medication: a drug with a heightened potential to cause significant patient harm if used in error [1.2.2, 1.2.5].

Quick Summary

High-risk medications are drugs that can cause significant patient harm when used incorrectly. This overview defines these medications, identifies key characteristics and classes, and outlines essential safety strategies for patients and providers.

Key Points

Definition: A high-risk medication is a drug with a heightened risk of causing significant patient harm or death when used in error [1.2.4].
Key Characteristics: These drugs often have a narrow therapeutic index, complex dosing, require frequent monitoring, or have a high potential for severe side effects [1.2.7].
Common Classes: Major high-risk classes include anticoagulants, opioids, insulins, chemotherapeutic agents, and concentrated electrolytes [1.3.2, 1.4.3].
Older Adults: The Beers Criteria lists medications that are potentially inappropriate for people over 65 due to increased risk of adverse effects [1.7.2, 1.7.3].
Safety Strategies: Key safety measures include standardizing procedures, using clinical alerts, performing independent double-checks, and thorough patient education [1.2.5, 1.5.3].
Patient's Role: Patients should maintain an accurate medication list, ask questions, and follow prescription instructions carefully to ensure their safety [1.5.2].
Statistical Impact: Adverse drug events are a major public health issue, with anticoagulants, diabetes agents, and antibiotics being leading causes of emergency department visits for ADEs [1.6.2].

Defining High-Risk Medications

A high-risk, or 'high-alert', medication is any drug that carries a heightened risk of causing significant injury or even death to a patient when used in error [1.2.4, 1.2.5]. While mistakes may not necessarily be more frequent with these drugs, the consequences of an error—such as incorrect dosing or administration—are far more devastating [1.4.6]. The Institute for Safe Medication Practices (ISMP) maintains and periodically updates lists of these medications to guide healthcare organizations in implementing special safeguards [1.4.4]. These safeguards can include standardizing procedures, improving access to drug information, using auxiliary labels, and employing redundancies like double-checks [1.2.5].

Characteristics of High-Risk Medications

Several factors can classify a medication as high-risk. These characteristics often overlap, meaning a single drug can fall into multiple categories [1.2.7].

Narrow Therapeutic Index (NTI): These drugs have a very small window between a dose that is effective and a dose that is toxic [1.8.1]. Small changes in the drug's concentration in the blood can lead to serious treatment failures or adverse reactions [1.8.2]. Examples include warfarin, lithium, digoxin, and phenytoin [1.8.1].
Complex Dosing and Monitoring: Some medications require complicated dosing schedules or frequent, specific monitoring to ensure safety and efficacy [1.2.6, 1.2.7]. For instance, once-weekly methotrexate has been linked to fatal overdoses when inadvertently taken daily [1.2.7]. Similarly, anticoagulants like warfarin require regular INR monitoring to prevent bleeding or clotting [1.2.3].
Severe Adverse Effects: The potential for severe side effects, such as respiratory depression with opioids or severe bleeding with antithrombotics, is a major characteristic [1.3.6].
Look-Alike, Sound-Alike (LASA) Names: Confusion between drugs with similar names or packaging can lead to dangerous errors [1.2.6]. Strategies to mitigate this include using both brand and generic names on prescriptions and employing 'tall man lettering' to emphasize differences in drug names [1.5.3].

Key Classes of High-Risk Medications

The ISMP and other health organizations identify several core classes of medications as high-risk. A common mnemonic used to remember some of these is 'A PINCH' [1.5.3].

A - Anti-infectives: (e.g., aminoglycosides like gentamicin) [1.3.2, 1.3.6]
P - Potassium and other electrolytes: (e.g., potassium chloride for injection) [1.3.2, 1.4.1]
I - Insulin: All forms of insulin are high-alert, with U-500 insulin requiring special emphasis due to its high concentration [1.4.1, 1.4.4].
N - Narcotics (Opioids) and other sedatives: These carry a high risk of respiratory depression and overdose [1.3.2, 1.3.6].
C - Chemotherapeutic Agents: Both oral and injectable chemotherapy drugs are high-risk [1.3.2, 1.4.3].
H - Heparin and other anticoagulants: (e.g., warfarin, direct oral anticoagulants) [1.3.2, 1.3.5].

Other significant high-risk classes include adrenergic agonists (e.g., epinephrine), anesthetic agents, and neuromuscular blocking agents [1.4.4].

Comparison of Common High-Risk Medication Classes


Medication Class	Primary Risk(s)	Common Examples	Management Strategies
Anticoagulants	Bleeding, Hemorrhage [1.2.3]	Warfarin, Heparin, Rivaroxaban [1.3.5]	Regular lab monitoring (INR for warfarin), patient education on signs of bleeding [1.2.3, 1.5.5].
Opioids	Respiratory Depression, Sedation, Overdose [1.3.6]	Morphine, Fentanyl, Oxycodone [1.3.6]	Careful dose titration, monitoring for sedation, access to naloxone [1.5.4].
Insulins	Hypoglycemia (low blood sugar) [1.2.3]	Insulin Aspart, Insulin Glargine, U-500 Insulin [1.4.1]	Independent double-checks of dosage, blood glucose monitoring, patient education on hypoglycemia symptoms [1.5.3].
Chemotherapy Agents	Myelosuppression, Toxicity	Methotrexate, Cyclophosphamide [1.6.1]	Specialized training for administration, strict protocols for handling and dosing [1.5.3].

Special Considerations for Older Adults: The Beers Criteria

Older adults (age 65+) are particularly vulnerable to adverse drug events due to age-related changes in how their bodies process medications [1.7.3, 1.2.1]. The American Geriatrics Society (AGS) Beers Criteria® is a list of potentially inappropriate medications (PIMs) for this population [1.7.3]. The list, updated every three years, helps clinicians avoid prescribing drugs where the risks may outweigh the benefits [1.7.3, 1.7.4]. It identifies medications to avoid or use with caution in older adults, especially those with certain health conditions or those with reduced kidney function [1.7.6].

Strategies for Safe Medication Management

Preventing errors with high-risk medications requires a multi-faceted approach involving healthcare systems, providers, and patients.

For Healthcare Providers and Systems:

Standardization: Standardize the ordering, storage, preparation, and administration of high-risk drugs [1.2.5].
Limiting Access: Restrict access to high-risk medications in patient care areas [1.2.5].
Clinical Decision Support: Use automated alerts in electronic health records to warn prescribers about potential issues [1.5.3].
Independent Double-Checks: Require two clinicians to independently verify critical steps, such as dose calculations for insulins or heparin [1.5.1].
Medication Reconciliation: Implement formal processes to create the most accurate medication list possible at all points of care transition, such as hospital admission and discharge [1.5.3].

For Patients and Caregivers:

Maintain a Medication List: Keep an updated list of all medications, including prescriptions, over-the-counter drugs, and supplements, and share it at every medical appointment [1.5.2, 1.5.5].
Ask Questions: Understand what each medication is for, how to take it, and what side effects to watch for. Ask your doctor or pharmacist if you are unsure [1.2.1, 1.5.2].
Follow Instructions: Take all medications exactly as prescribed. Do not stop taking a medicine without consulting your provider [1.5.5].
Use a Pill Organizer: A pillbox can help ensure you take the correct dose at the right time, especially when managing multiple medications [1.5.5].

Conclusion

High-risk medications are essential for treating many conditions, but their potential for causing significant harm necessitates a high degree of caution. Understanding which drugs are high-risk, recognizing their defining characteristics, and implementing robust safety strategies are critical for both healthcare providers and patients. Through diligent management, clear communication, and patient engagement, the risks associated with these powerful medications can be effectively minimized, leading to safer and more effective healthcare for everyone.

For more detailed guidance, consider consulting the Institute for Safe Medication Practices (ISMP).

Frequently Asked Questions

A medication is considered high-risk if it has a heightened potential to cause significant harm, injury, or death to a patient if an error occurs during its use. This is often due to a narrow therapeutic index, complex dosing, or the potential for severe side effects [1.2.2, 1.2.4].

Not necessarily. While errors may not be more common with high-risk medications compared to others, the consequences of an error are significantly more devastating to patients [1.2.5].

A narrow therapeutic index means there is a small difference between the dose of a drug that is effective and the dose that can cause toxicity or serious harm. Examples include warfarin and lithium [1.8.1].

Common high-risk medication classes include anticoagulants (like warfarin), opioids (like morphine), insulins, oral hypoglycemics, chemotherapeutic agents, and concentrated electrolytes (like potassium chloride) [1.3.2, 1.4.4].

The Institute for Safe Medication Practices (ISMP) is an organization that provides guidance on medication safety. It creates and regularly updates a list of high-alert medications to help healthcare providers implement special safeguards to reduce the risk of errors [1.4.4].

The Beers Criteria is a list of potentially inappropriate medications for adults aged 65 and older. It helps guide healthcare providers in prescribing safer alternatives for this population, who are more susceptible to adverse drug effects [1.7.1, 1.7.3].

Patients should maintain a complete and updated list of all their medications (prescription, over-the-counter, and supplements) and share it with all their healthcare providers. It is also crucial to ask questions and fully understand what the medication is for and how to take it correctly [1.5.5].