Treatment of protein S deficiency occurs either in patients who have had a venous thrombosis or in patients with asymptomatic carrier states without a thrombotic event, depending on the decisions made by the patient's health care provider. Following a venous thrombosis, patients are treated with anticoagulant
drugs (blood thinners) including heparin
followed by warfarin
. In most patients, specialists recommend 6-9 months of initial treatment with warfarin. The question of whether to continue lifelong warfarin in patients with identified protein S deficiency after their first thrombotic event is controversial. If the first thrombotic event was life threatening or occurred in multiple or unusual sites (i.e. cerebral veins, mesenteric veins), most experts recommend lifelong therapy initially. If brought about especially abruptly by a strong event (i.e. trauma, surgery) and the thrombosis did not meet the criteria of life threatening or multiple or unusual sites, some experts argue that these patients may have a lower risk of recurrence and deserve a trial without warfarin after 9 months.
In patients who are asymptomatic carriers of protein S deficiency, the goal of therapy is prevention of the first thrombosis. In such patients, drugs that predispose to thrombosis, including oral contraceptives should be avoided. If these patients require surgery or an orthopedic injury occurs, prophylaxis with heparin may become necessary.