Nattokinase Safety in Chronic Liver Disease
Nattokinase lacks high-quality clinical safety data in patients with hepatitis, cirrhosis, or other chronic liver disease. [1] Available regulatory review concluded that evidence from human studies is insufficient to conclude overall safety of nattokinase products. [1]
Bleeding Risk With Concomitant Anticoagulant or Antiplatelet Therapy
Nattokinase has fibrinolytic and antithrombotic activity and is associated with concern for increased bleeding risk when combined with anticoagulant and antiplatelet therapies. [1] A safety evaluation by EFSA noted human studies in which coagulation parameters changed and adverse events included haematemesis in a small uncontrolled stroke study that also used heparin plus antiplatelet therapy. [1] Regulatory assessment concluded that the overall evidence base is insufficient to establish safety in the setting of concurrent anticoagulant use. [1]
Liver Disease and Elevated Liver Enzymes
Human safety evidence in people with liver disease is limited. [1] The EFSA dossier review explicitly characterized human evidence as low power with inconsistencies and concluded evidence is insufficient to conclude safety overall. [1] In a small stroke study summarized within the EFSA review, adverse events reported included AST and ALT increases. [1]
Practical Safety Position for Initiation
Initiation of nattokinase in patients with known liver disease should be avoided in the absence of robust safety data. [1] Initiation is not recommended when the patient is taking anticoagulant or antiplatelet therapy because of a plausible additive bleeding risk and insufficient evidence for safety with concurrent blood-thinning drugs. [1]
Evidence Base Limitations
Randomized controlled trials with adequate liver-disease representation and adequate bleeding-outcome ascertainment are not available to guide safe initiation in hepatitis or cirrhosis. [1] Regulatory review found insufficient evidence overall due to low study power and inconsistency across studies. [1]
Monitoring Considerations When Use Occurs
If nattokinase is nonetheless being considered despite limited safety evidence, baseline and follow-up monitoring of bleeding symptoms and liver enzymes is clinically prudent because enzyme elevations were reported as adverse events in reviewed studies and bleeding risk is the key safety concern with concurrent antithrombotic therapy. [1]
Bottom-Line Clinical Recommendation
Nattokinase is not established as safe for initiation in chronic liver disease and is particularly concerning for patients receiving anticoagulant or antiplatelet therapy due to uncertain overall safety and potential bleeding risk. [1]