While reviewing medication charts, the nurse observed that one patient received a wrong medication that...

The best nursing action for reporting a medication error is to report and document the incident immediately. Prompt reporting ensures that the error is addressed quickly to prevent harm to the patient, allows for accurate documentation, and initiates the process for investigation and prevention of future errors. While assessing the patient and informing a senior nurse are also necessary steps, immediate documentation is the priority to ensure patient safety and compliance with legal and professional standards.