High-Alert Medications in Community/Ambulatory Care Settings

High-alert medications are drugs that bear a heightened risk of causing significant patient harm when they are used in error. Although mistakes may or may not be more common with these drugs, the consequences of an error are clearly more devastating to patients.

Use ISMP's List of High-Alert Medications in Community/Ambulatory Care Settings to determine which medications in your practice site require special safeguards to reduce the risk of errors and minimize harm. Strategies may include:

  • Standardizing the prescribing, storage, preparation, dispensing, and administration of these medications 

  • Improving access to information about these drugs 

  • Using auxiliary labels and automated alerts

  • Employing redundancies

  • Providing mandatory patient education

Ambulatory care sites such as long-term care facilities, long-term acute care facilities, dialysis facilities, ambulatory surgery centers, and the pharmacies that provide services to them should also reference the ISMP List of High-Alert Medications in Long-Term Care (LTC) Settings and/or the ISMP List of High-Alert Medications in Acute Care Settings.

How to cite: Institute for Safe Medication Practices (ISMP). ISMP List of High-Alert Medications in Community/Ambulatory Care Settings. ISMP; 2021.

Classes/Categories of Medications

Antithrombotic agents, oral and parenteral, including:

  • Anticoagulants (e.g., warfarin, low molecular weight heparin, unfractionated heparin)

  • Direct oral anticoagulants and factor Xa inhibitors (e.g., dabigatran, rivaroxaban, apixaban, edoxaban)

  • Direct thrombin inhibitors (e.g., dabigatran)

Chemotherapeutic agents

  • Oral and parenteral chemotherapy (e.g., capecitabine, cyclophosphamide)

  • Oral targeted therapy and immunotherapy (e.g., palbociclib [IBRANCE], imatinib [GLEEVEC], bosutinib [BOSULIF])

  • Excludes hormonal therapy

Immunosuppressant agents, oral and parenteral (e.g., azaTHIOprine, cycloSPORINE, tacrolimus)

Insulins, all formulations and strengths (e.g., U-100, U-200, U-300, U-500)

Medications contraindicated during pregnancy (e.g., bosentan, ISOtretinoin)

Moderate and minimal sedation agents, oral, for children (e.g., chloral hydrate, midazolam, ketamine [using the parenteral form])

Opioids, all routes of administration (e.g., oral, sublingual, parenteral, transdermal), including liquid concentrates, immediate- and sustained-release formulations, and combination products with another drug

Pediatric liquid medications that require measurement

Sulfonylurea hypoglycemics, oral (e.g., chlorproPAMIDE, glimepiride, glyBURIDE, glipiZIDE, TOLBUTamide)

Specific Medications


EPINEPHrine, IM, subcutaneous

Insulin U-500 (special emphasis)*


Methotrexate, oral and parenteral, nononcologic use (special emphasis)*


Valproic acid

*All oral and parenteral chemotherapy, and all insulins are considered high-alert medications. These specific medications have been singled out for special emphasis to bring attention to the need for distinct strategies to prevent the types of errors that occur with these medications.


Based on error reports submitted to the ISMP National Medication Errors Reporting Program (ISMP MERP), reports of harmful errors in the literature, studies that identify the drugs most often involved in harmful errors, and input from practitioners and safety experts, ISMP created and has periodically updated a list of high-alert medications in community and ambulatory care settings. The original list was developed in 2008, which included input from community pharmacy practitioners who participated in focus groups or responded to an ISMP survey on the topic. To update the list, practitioners were once again surveyed. To assure relevance and completeness, the clinical staff at ISMP, members of ISMP’s community/ambulatory care advisory board, and other safety and clinical experts in the US were asked to review the list and potential changes. This current list reflects the collective thinking of all who provided input.

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This list includes abbreviations, symbols, and dose designations that have been frequently misinterpreted and involved in harmful or potentially harmful medication errors.