Final answer:
The nurse should report the error following facility protocols and document the correct information in a new entry, maintaining the integrity of the patient's medical record.
Step-by-step explanation:
When a nurse realizes that an incorrect medication has been documented in a patient's chart, the correct action to take is to report the error following facility protocols. It is important to never alter a medical record as it can compromise patient safety and violate both legal and ethical standards. Instead, the nurse should make a new entry in the chart, clearly indicating the error and the correct medication, while also following any specific procedures the healthcare facility has in place for correcting documentation errors. Reporting and correcting errors transparently ensures the integrity of the patient's medical record and maintains trust in the healthcare system.