What is the appropriate action a nurse must take before administering warfarin?

Before administering warfarin, it's crucial to check lab values, specifically the PT (prothrombin time) and INR (International Normalized Ratio). Warfarin is an anticoagulant that requires careful monitoring of these values to ensure the medication is effective while minimizing the risk of bleeding complications.

The PT and INR provide essential information about how well the blood is clotting and whether the patient is in a safe therapeutic range for warfarin usage. If the INR is too low, the patient is at risk of clot formation; if it is too high, the risk of serious bleeding increases. Therefore, verifying these lab values is an essential step in ensuring patient safety and achieving the desired therapeutic outcomes when administering warfarin.

While checking previous doses, assessing for allergies, and inquiring about dietary restrictions are important nursing actions, they do not take precedence in ensuring the immediate safety and efficacy of warfarin administration. Monitoring lab values is the most direct way to guide the nurse in making an appropriate and safe decision regarding the medication.