Final answer:
The nurse should first review the client's medication list when completing medication reconciliation for an older adult client on multiple medications.
Step-by-step explanation:
The nurse should first review the client's medication list when completing medication reconciliation for an older adult client on multiple medications. This is important to ensure accuracy and to identify any potential drug interactions or omissions. By reviewing the medication list, the nurse can gather information about the client's current medications, dosages, and frequency of administration.