A nurse is administering 4 mg of hydromorphone to a client by mouth every 4 hr. The medication is provided as hydromorphone 8 mg per tablet. Which of the following actions is appropriate for the nurse to take?

The correct answer is B: Dispose of the remaining medication while another nurse observes. This is because hydromorphone is a controlled substance and must be disposed of properly in the presence of another nurse as a witness to maintain accountability and prevent diversion. Returning the medication to the pharmacy (A) is not appropriate as it could lead to incorrect administration. Storing the remaining half of the pill in the automated medication dispensing system (C) or placing it in the unit-dose package (D) can lead to potential errors or misuse.