A 38-year-old man is evaluated in the hospital on day 4 of admission for an acute left lower extremity deep vein thrombosis. He has a known history of primary antiphospholipid syndrome. Upon admission, he was started on a continuous intravenous unfractionated heparin infusion and oral warfarin.
Daily INR values since admission are as follows:
| Hospital Day | INR Result |
|---|---|
| Day 1 | 1.1 |
| Day 2 | 1.2 |
| Day 3 | 1.7 |
| Day 4 (today) | 2.4 |
Today's laboratory results show an activated partial thromboplastin time (aPTT) of 68 seconds (therapeutic goal: 60-80 seconds). His platelet count is 210,000/mm³ (baseline 225,000/mm³ on admission). The patient reports that his leg swelling has significantly improved, though he still experiences mild residual leg pain. He has no signs of clinical bleeding.
Which of the following is the most appropriate next step in the management of this patient's pharmacotherapy?
- ADiscontinue warfarin and transition to oral rivaroxaban
- BDiscontinue the unfractionated heparin infusion and continue oral warfarin
- Continue both the unfractionated heparin infusion and oral warfarinCevap
- DHold the next dose of warfarin and continue the unfractionated heparin infusion
- EPrescribe oral naproxen for the residual leg pain and continue the current anticoagulants