A nurse is caring for four clients. After administering morning medications, she realizes that the nifedipine prescribed for one client was inadvertently administered to another client. Which of the following actions should the nurse take first?

A. Notify the client's provider. Notifying the physician is a necessary step in the medication error protocol but is not the immediate priority. The nurse must first determine the physiological impact of the error on the client before reporting. Clinical data regarding the patient's current status is essential for the provider to determine necessary corrective orders. B. Administer the medication to the correct client. Correcting the original omission is secondary to managing the potential toxicity or adverse effects in the client who received the wrong drug. Nifedipine is a potent calcium channel blocker that can cause sudden, severe hypotension. The nurse must focus all immediate resources on the safety of the patient currently at risk. C. Fill out an occurrence form. Documentation of the incident in an occurrence or incident report is an administrative requirement for quality improvement and risk management. This task is performed only after the client has been stabilized and the provider has been notified. Reporting should never supersede direct clinical assessment and intervention during a potential medication-related emergency. D. Check the client's vital signs. The priority action is to assess the client who received the incorrect medication for adverse physiological responses. Nifedipine can cause significant vasodilation, resulting in profound hypotension and compensatory tachycardia. Establishing a baseline of vital signs allows the nurse to prioritize interventions and provide accurate data to the healthcare provider.