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

A. Fill out an incident report: While documentation is essential for quality improvement and accountability, it is not the immediate priority. The client’s safety must be addressed before any administrative action is taken. B. Report the incident to the nurse manager: Notifying the manager is an important step in the reporting chain, but it should occur after ensuring the client is stable and receiving appropriate clinical care. C. Notify the provider: The provider must be informed to assess for possible interventions or antidotes, but the nurse should first collect the client’s current clinical status to report meaningful information. D. Measure the client's vital signs: Assessing the client’s condition is the first priority after a medication error. Vital signs provide critical information on the client’s immediate response and help guide the next steps in managing the error.