A nurse is caring for a client prescribed Lithium. Which nursing action is most appropriate regarding monitoring serum lithium levels and maintaining adequate fluid and sodium intake?
1Initiate warfarin therapy following a 5-day course of enoxaparin, because providing low-molecular-weight heparin alone before warfarin reduces the risk of paradoxical clotting in the initial phase of oral anticoagulation.✓ Correct answer
2Discontinue enoxaparin after 2 days of concurrent therapy, since warfarin reaches its full anticoagulant effect by the second day and the INR will be in the therapeutic range without further overlap.
3Continue enoxaparin and warfarin together (overlap) for at least 5 days AND until the INR has been within the therapeutic range (typically 2.0-3.0) for at least 24 hours, then discontinue enoxaparin.
4Stop warfarin and continue enoxaparin monotherapy, because low-molecular-weight heparin provides more reliable anticoagulation for DVT than warfarin, which is no longer indicated for long-term prevention.
Explanation
When administering Lithium, key nursing considerations include monitoring patient status, checking critical laboratory values, and providing appropriate safety education. Unsafe practices such as stopping medications abruptly or doubling missed doses are incorrect.
Clinical reasoning summary Warfarin transition rule Warfarin inhibits the synthesis of new vitamin-K-dependent clotting factors (II, VII, IX, X) and proteins C, S. Existing factors must clear before INR rises into therapeutic range — this typically takes 5-7 days. During the warm-up period, the patient is paradoxically pro-thrombotic because protein C (anticoagulant) drops faster than factor II.
Standard transition (CHEST/ACC guideline): • Start warfarin and parenteral anticoagulant (UFH, LMWH, or fondaparinux) on day 1 simultaneously when feasible. • Overlap for at least 5 days AND until INR ≥2.0 for at least 24 hours. • Then stop the parenteral agent and continue warfarin. • Mechanical valves, large clot burden, malignancy may require longer parenteral therapy.
Option 1 (stop tomorrow) leaves the patient unprotected. Option 3 (stop warfarin) defeats the long-term oral plan. Option 4 (delay warfarin) is wrong — warfarin and parenteral start together to overlap.