Final answer:
Anticoagulants are the category of medication on ISMP's list of High-Alert Medications, due to their potential for significant harm if misused.
Step-by-step explanation:
The medication category on ISMP's list of High-Alert Medications from the given options is anticoagulants. High-Alert Medications are those that have a heightened risk of causing significant patient harm when used in error. Although not on the list mentioned, other options like antihypertensive medications play an essential role in treating hypertension and require careful management to achieve desired blood pressure control without causing harmful effects.