PTCB Quiz Prep

High-Alert Medication Practice Questions with Answers

Updated · aligned to the 2026 PTCE outline

The drug classes that cause the most harm when they go wrong, and the double-check systems built around them.

10 questionsAnswers includedUntimedEvery answer cited100% free

Key takeaways

  • High-alert means high harm when misused, not high error frequency.
  • The recurring classes: insulin, anticoagulants (heparin, warfarin), opioids, and concentrated electrolytes such as potassium chloride injection.
  • Standard safeguards: independent double checks, standardized concentrations, and removing concentrated electrolytes from floor stock.
  • ISMP publishes separate high-alert lists for acute care, community and long-term care settings.

High-alert medications are not the drugs most likely to be involved in an error. They are the drugs where an error is most likely to seriously harm the patient. ISMP maintains the lists, and the distinction matters because it is what the PTCE asks about.

Every question here is untimed with the answer visible below it. These come from the Patient Safety and Quality Assurance domain, which is 23.75% of the 2026 exam.

Want the same material as a timed, randomized run instead? Try the timed Patient Safety quiz and the Patient Safety & Quality Assurance domain guide.

All 10 high-alert medications questions and answers

Each answer is followed by an explanation and a link to the primary source it was checked against.

  1. 1. Which statement correctly defines a high-alert medication?

    • A.A drug that is involved in errors more often than any other medication
    • B.A drug that must always be stored in a locked safe with a perpetual inventory
    • C.A drug that requires REMS program enrollment before dispensing
    • D.A drug that bears a heightened risk of causing significant patient harm when it is used in error

    Answer: D. A drug that bears a heightened risk of causing significant patient harm when it is used in error

    ISMP defines high-alert medications as drugs that bear a heightened risk of causing significant patient harm when used in error. Mistakes with these drugs are not necessarily more common, but the consequences of an error are clearly more devastating. That is why they warrant special safeguards.

    Source: home.ecri.org

  2. 2. Which class of drugs appears on the ISMP List of High-Alert Medications in Acute Care Settings?

    • A.Neuromuscular blocking agents such as succinylcholine, rocuronium, and vecuronium
    • B.Proton pump inhibitors such as omeprazole
    • C.HMG-CoA reductase inhibitors such as atorvastatin
    • D.Topical antifungals such as clotrimazole

    Answer: A. Neuromuscular blocking agents such as succinylcholine, rocuronium, and vecuronium

    Neuromuscular blocking agents are on the acute care high-alert list because accidental administration to a patient who is not mechanically ventilated causes paralysis and death. The list also includes classes such as insulin, opioids, antithrombotics, and concentrated electrolytes. PPIs, statins, and topical antifungals are not high-alert classes.

    Source: ismp.org

  3. 3. Which specific medication did ISMP add to its List of High-Alert Medications in Acute Care Settings in the 2024 update?

    • A.Naloxone injection
    • B.Tolvaptan
    • C.Tranexamic acid injection
    • D.Alprostadil

    Answer: C. Tranexamic acid injection

    ISMP added tranexamic acid injection to the specific medications section of the 2024 acute care list. Vials are often confused with look-alike anesthetic vials stored in surgical areas, and accidental neuraxial injection is a potent neurotoxin with roughly 50 percent mortality. Naloxone, tolvaptan, and alprostadil were suggested by survey respondents but were not added.

    Source: ismp.org

  4. 4. On the ISMP acute care high-alert list, which insulin product is singled out for special emphasis?

    • A.Insulin glargine U-100
    • B.Insulin U-500
    • C.NPH insulin
    • D.Insulin lispro U-100

    Answer: B. Insulin U-500

    All subcutaneous and IV insulin is treated as a high-alert class, but U-500 insulin receives special emphasis on the list. Its five-fold concentration makes dosing mix-ups especially dangerous, and 100 percent of practitioners in ISMP's 2023 survey considered it high-alert. The other insulins are covered by the general class listing.

    Source: ismp.org

  5. 5. A nurse removes a 250 mL bag from the heparin bin of an automated dispensing cabinet, and barcode scanning before administration reveals it is actually potassium chloride for injection concentrate. What does this reported event best illustrate?

    • A.Barcode scanning acting as a final safeguard that caught a look-alike storage error involving two high-alert drugs
    • B.A prescribing error that only the physician could have prevented
    • C.An acceptable substitution because both products are intravenous solutions
    • D.A billing discrepancy with no patient safety significance

    Answer: A. Barcode scanning acting as a final safeguard that caught a look-alike storage error involving two high-alert drugs

    ISMP published this close call in January 2024: look-alike B. Braun bags of heparin and potassium chloride concentrate were stocked in the same cabinet bin. Both are high-alert medications, and infusing concentrated potassium is potentially fatal. The barcode scan prior to administration was the redundancy that intercepted the error.

    Source: ismp.org

  6. 6. Which category appears on the ISMP List of High-Alert Medications in Community/Ambulatory Healthcare?

    • A.Adult multivitamin gummies
    • B.Topical corticosteroid creams
    • C.Ophthalmic lubricant drops
    • D.Pediatric liquid medications that require measurement

    Answer: D. Pediatric liquid medications that require measurement

    The community/ambulatory high-alert list includes pediatric liquids that require measurement because dosing errors with droppers and syringes are common and harmful. Other entries include insulin in all formulations, opioids, oral chemotherapy, immunosuppressants, warfarin, and non-oncologic methotrexate. The distractor products do not carry heightened risk of significant harm.

    Source: ismp.org

  7. 7. A new prescription reads 'methotrexate 2.5 mg PO daily' for a patient whose profile lists rheumatoid arthritis. Why must the technician alert the pharmacist before processing it?

    • A.Methotrexate is a Schedule II controlled substance requiring a hard copy
    • B.Non-oncologic methotrexate is a high-alert drug normally taken weekly, so a daily schedule may be a life-threatening error
    • C.Methotrexate may not legally be dispensed by community pharmacies
    • D.The 2.5 mg strength was discontinued and must be compounded

    Answer: B. Non-oncologic methotrexate is a high-alert drug normally taken weekly, so a daily schedule may be a life-threatening error

    Methotrexate for non-oncologic use appears on ISMP's community/ambulatory and acute care high-alert lists. For conditions like rheumatoid arthritis it is typically dosed once weekly, and accidental daily dispensing has caused fatal toxicity. The pharmacist must confirm the intended weekly regimen with the prescriber before the prescription proceeds.

    Source: ismp.org

  8. 8. Which of the following is a safeguard ISMP specifically recommends for managing high-alert medications?

    • A.Dispensing them only in 90-day supplies
    • B.Requiring patients to sign a liability waiver before pickup
    • C.Limiting access to the drugs and using auxiliary labels and automated alerts
    • D.Storing them alphabetically alongside all other stock

    Answer: C. Limiting access to the drugs and using auxiliary labels and automated alerts

    ISMP's recommended strategies include standardizing ordering, storage, preparation, and administration; improving access to drug information; limiting access; using auxiliary labels and automated alerts; and employing redundancies such as independent double checks. Alphabetical storage with regular stock actually increases look-alike risk. Supply limits and waivers are not ISMP safeguards.

    Source: home.ecri.org

  9. 9. Which product appears on the ISMP acute care high-alert list with a specific container-size qualifier?

    • A.Sterile water for injection, inhalation, and irrigation in containers of 100 mL or more
    • B.Normal saline flushes in prefilled syringes of 10 mL or more
    • C.Dextrose 5% in water in bags of 500 mL or more
    • D.Lactated Ringer's solution in bottles of 250 mL or more

    Answer: A. Sterile water for injection, inhalation, and irrigation in containers of 100 mL or more

    The list includes sterile water for injection, inhalation, and irrigation, excluding pour bottles, in containers of 100 mL or more. Large sterile water containers can be mistaken for ready-to-infuse IV solutions, and infusing plain water intravenously is dangerous because it is hypotonic. The other fluids listed are not high-alert entries.

    Source: ismp.org

  10. 10. Why is promethazine injection included on the ISMP acute care high-alert list?

    • A.It causes fatal arrhythmias when taken orally
    • B.It is a potent opioid with a high risk of respiratory depression
    • C.It is a vesicant that can cause severe tissue injury, so FDA recommends deep intramuscular injection rather than IV administration
    • D.It requires hemodialysis dose adjustments in every patient

    Answer: C. It is a vesicant that can cause severe tissue injury, so FDA recommends deep intramuscular injection rather than IV administration

    Promethazine injection is highly caustic to blood vessels and surrounding tissue, and errors have led to gangrene and amputation. FDA required labeling updates recommending deep intramuscular administration instead of IV use; if given IV, it should be diluted and infused through a large vein or central line. ISMP added the drug to the high-alert list in 2007 and its best practices recommend hospitals remove injectable promethazine from formularies.

    Source: fda.gov

High-Alert Medications: FAQ

What is a high-alert medication?

A drug that carries a heightened risk of significant patient harm when it is used in error. The classification is about the severity of the consequence, not how often mistakes happen. ISMP maintains the reference lists.

What are the most commonly tested high-alert drugs?

Insulin, anticoagulants such as heparin and warfarin, opioids, and concentrated electrolytes, particularly potassium chloride for injection. Neuromuscular blockers and chemotherapy agents also appear.

What safeguards apply to high-alert medications?

Independent double checks before dispensing or administration, standardized concentrations and dosing, auxiliary labeling, automated dispensing cabinet alerts, and keeping concentrated electrolytes out of general floor stock.

Official sources checked

Every answer above was written against a primary source and verified independently. These are the 4 sources behind this set.

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