If I were the nursing manager, I would follow protocol for disciplinary action depending on the organization, but disciplinary action would need to be had following a formal meeting to discuss the scenario. Also, it is important to point out the intention in this case. Medication errors made intentionally versus unintentionally should be handled differently and need to be established in this case.
American Nurses Association (ANA). (2015). Code of Ethics for Nurses with Interpretive Statements. ANA. https://www.nursingworld.org/practice-policy/nursing-excellence/ethics/code-of-ethics-for-nurses/coe-view-only/
Davic, C. (2017). The importance of professional accountability. Nursing Made Incredibly Easy! https://journals.lww.com/nursingmadeincrediblyeasy/fulltext/2017/11000/the_importance_of_professional_accountability.1.aspx