The effect of warfarin on the aPTT is not well documented, although it appears that the aPTT is increased following initiation of warfarin and this effect may be cumulative with successive doses. Some patients may be at risk of over-coagulation when heparin and warfarin are combined. When the aPTT is checked at 6 hours or longer after a dosage change, steady-state kinetics can be assumed. Adjust dosages cautiously Dosage changes must be made slowly, and the aPTT must be checked every six hours until stable, then daily during the course of therapy. Close monitoring of the patient is essential.
Heparin dose is clearly the most important determinant of minor bleeding episodes.
Aging is a risk factor for total and major bleeding complications. Because of age-related changes in pharmacokinetic characteristics of heparin, aging is associated with an increase in heparin levels after standard doses. Heparin dose requirements are decreased in the elderly. Severe hepatic failure Reversal of heparin effects Minor bleeding Stop heparin Monitor vital signs, aPTT, Hgb, Hct, platelet count. Major bleeding Stop heparin Monitor vital signs, aPTT, Hgb, Hct, platelet count.