Which of the following is an example of a medication error?

The omission of a prescribed medication is a clear example of a medication error because it directly impacts a patient’s treatment plan and health outcomes. When a prescribed medication is not administered as intended, it can lead to a failure in achieving therapeutic goals, worsening of the patient's condition, or triggering adverse effects associated with the abrupt cessation of therapy.

In the context of proper medication administration, each prescribed medication plays a vital role in managing a patient’s health. Therefore, the failure to provide a dose can compromise the effectiveness of the treatment and may have serious health consequences for the patient. This phenomenon highlights the critical importance of adherence to medication schedules and ensuring that all prescribed treatments are properly administered.

The other options involve actions that are part of appropriate care and management. Instructing a resident on medication use, providing dietary advice, and performing a medication inventory are all supportive activities that contribute to medication safety but do not constitute errors in themselves. They are essential elements of patient education and care that help ensure effective and safe medication management.