Pharmacology Proctored ATI Practice Exam 2024 - Free Pharmacology Practice Questions and Study Guide.

After inadvertently administering nifedipine to the wrong client, the first action a nurse should take is to check the client's vital signs. This is important because nifedipine is a calcium channel blocker that can cause a significant decrease in blood pressure, putting the client at risk for complications such as fainting or dizziness. This action should be taken immediately to address any potential adverse effects and ensure the safety of the client. Informing the healthcare provider should also be done as soon as possible, but it is not the first action that should be taken. Administering the antidote or documenting the error in the client's chart are not appropriate actions in this situation, as there is no antidote for nifedipine and documenting the error should come after addressing the client's immediate safety. Therefore, option B is the correct answer.