Effect of early or delayed administration of warfarin with heparin on thrombosis in pulmonary thromboembolism

Med Princ Pract. 2011;20(2):181-6. doi: 10.1159/000319767. Epub 2011 Jan 20.


Objective: The aim of this study was to investigate the effect of early or delayed warfarin administration with unfractionated heparin (UFH) on coagulation parameters in pulmonary thromboembolism (PTE).

Patients and methods: This study was performed between November 2006 and July 2007. Thirty-three patients with PTE were sequentially slotted to early (n = 16) and delayed (n = 17) warfarin treatment groups. In the early group, both UFH infusion and warfarin were started simultaneously and in the delayed group, warfarin was added (1-3 days later) based on when partial thromboplastin time reached the therapeutic level with UFH. The proteins C and S, D-dimer, hematocrit levels, and platelet counts for all patients were studied prior to treatment and 6, 24, and 48 h after warfarin treatment. In order to determine the overall effect of early and delayed warfarin treatment on clot formation, a thromboelastogram was performed simultaneously.

Results: In both groups, a similar chronological decrease in protein C levels reaching maximum at 24 h with warfarin treatment was observed. However, intragroup or intergroup decreases in protein S levels were not different. On thromboelastogram, INTEM and EXTEM clotting times were significantly prolonged chronologically, but this prolongation was not different between groups.

Conclusion: The suppressor effect of warfarin on proteins C and S in the early period of double anticoagulant treatment did not appear to aggravate the risk of thrombosis in patients with PTE in whom warfarin was started simultaneously with UFH.

MeSH terms

  • Aged
  • Anticoagulants / administration & dosage
  • Anticoagulants / therapeutic use*
  • Female
  • Fibrin Fibrinogen Degradation Products
  • Hematocrit
  • Humans
  • Length of Stay
  • Male
  • Partial Thromboplastin Time
  • Platelet Count
  • Protein C
  • Protein S
  • Pulmonary Embolism / drug therapy*
  • Risk Factors
  • Statistics, Nonparametric
  • Thrombelastography
  • Time Factors
  • Warfarin / administration & dosage
  • Warfarin / therapeutic use*


  • Anticoagulants
  • Fibrin Fibrinogen Degradation Products
  • Protein C
  • Protein S
  • fibrin fragment D
  • Warfarin