Do Steroids Have Anticoagulant Properties?
No, steroids do not have anticoagulant properties—in fact, corticosteroids have procoagulant effects that increase thrombotic risk, while sex hormones (estrogen/progesterone) significantly increase venous thromboembolism risk 2-3 fold. 1
Corticosteroids and Coagulation
Procoagulant Effects
Corticosteroids activate the coagulation system rather than inhibit it:
Clotting factor elevation: Short-term glucocorticoid treatment (5 days of dexamethasone) increases factor VII by 13%, factor VIII by 27%, factor XI by 6%, and fibrinogen by 13% in healthy volunteers 2
Thrombin generation: A 10-day prednisolone course in healthy subjects significantly increases peak thrombin, velocity index, PAI-1, and von Willebrand factor compared to placebo, creating a procoagulant state 3
Maintained hemostatic balance: While glucocorticoids increase both procoagulant factors (VIII, IX, XI, XII) and anticoagulants (antithrombin, protein C), the overall hemostatic balance is maintained rather than shifted toward anticoagulation 4
Clinical Implications for Thrombosis Risk
Patients on corticosteroids require thromboprophylaxis, not reduced anticoagulation:
Patients with acute severe ulcerative colitis treated with high-dose intravenous corticosteroids (methylprednisolone 60 mg daily or hydrocortisone 100 mg 6-hourly) must receive prophylactic low-molecular weight heparin due to 2-3 fold higher VTE risk 5
The FDA drug label for methylprednisolone explicitly states: "The effect of methylprednisolone on oral anticoagulants is variable. There are reports of enhanced as well as diminished effects of anticoagulants when given concurrently with corticosteroids. Therefore, coagulation indices should be monitored to maintain the desired anticoagulant effect." 6
Context-Dependent Effects
The impact of glucocorticoids varies by clinical situation 7:
- During active inflammation: Glucocorticoids increase PAI-1 (antifibrinolytic) while decreasing von Willebrand factor and fibrinogen
- Peri-operative use: Inhibits the surgery-induced increase in tissue-type plasminogen activator
- In healthy volunteers: Clear increases in factor VII, VIII, and XI activity
Sex Hormones (Estrogen/Progesterone)
These steroids have the strongest prothrombotic effects:
- Combined estrogen-progesterone therapy increases thrombotic risk 2-3 fold compared to non-users 1
- Hormone replacement therapy more than doubles VTE risk (RR 2.14; 95% CI 1.64-2.81) 1
- Estrogen increases factor VII activity, D-dimer, and prothrombin F1.2 while decreasing antithrombin III and tissue factor pathway inhibitor 1
Critical Clinical Caveat
Bleeding risk with intranasal corticosteroids is local, not systemic:
- Intranasal corticosteroids increase nosebleed risk (RR 2.74) through local mucosal effects, not systemic anticoagulation 8
- This represents local tissue effects rather than systemic hemostatic changes
Practical Management
When prescribing corticosteroids:
- Monitor coagulation indices if patient is on anticoagulants, as steroids can unpredictably enhance or diminish anticoagulant effects 6
- Provide thromboprophylaxis for hospitalized patients on high-dose IV corticosteroids 5
- Consider increased VTE risk in cancer patients receiving steroids combined with chemotherapy or antiangiogenic agents 1
- Avoid assuming anticoagulant properties—the opposite is true for systemic effects