A nurse realizes that the wrong medication has been administered to a client. Which of the following actions should the nurse take first?

The first priority after a medication error is client safety — assessing the client's current condition. Measuring vital signs identifies any immediate physiological response to the wrong medication. After assessment, the nurse notifies the provider with the assessment data, then the nurse manager, and then completes the incident report. Documentation and reporting are important but secondary to evaluating client safety.