Can Humira (adalimumab) cause hematomas?

Adalimumab (Humira) and Risk of Hematomas

Yes, adalimumab (Humira) can cause hematomas due to its potential to induce thrombocytopenia and other hematologic abnormalities that increase bleeding risk.

Mechanism and Evidence

Adalimumab, a TNF-alpha inhibitor, has been documented in the FDA drug label to cause hematologic complications:

• The FDA label specifically states: "Adverse reactions of the hematologic system, including medically significant cytopenia (e.g., thrombocytopenia, leukopenia) have been infrequently reported with HUMIRA" 1
• The drug label further advises patients to "seek immediate medical attention if they develop signs and symptoms suggestive of blood dyscrasias or infection (e.g., persistent fever, bruising, bleeding, pallor)" 1

Clinical Presentations of Adalimumab-Related Bleeding Risk

Adalimumab-induced hematomas may present as:

1. Spontaneous hematomas - occurring without apparent trauma
2. Post-injection site hematomas - one of the most common side effects is injection site reactions
3. Excessive bruising - may be widespread or localized
4. Prolonged bleeding after minor trauma or procedures

Case Reports and Severity

Several case reports document serious hematologic complications:

• A case of severe adalimumab-induced thrombocytopenia in a patient with Crohn's disease who did not respond to standard therapy for thrombocytopenia 2
• A case of adalimumab-induced thrombocytopaenic microangiopathy requiring plasma exchange therapy 3

Risk Factors for Adalimumab-Related Hematomas

Patients at increased risk include those with:

• Pre-existing bleeding disorders
• Concurrent use of anticoagulants or antiplatelet agents
• History of thrombocytopenia
• Advanced age
• Renal or hepatic impairment

Monitoring and Management

For patients on adalimumab:

1. Baseline assessment: Complete blood count before initiating therapy
2. Regular monitoring: Periodic blood counts during treatment
3. Vigilance for symptoms: Bruising, petechiae, bleeding gums, hematuria
4. Prompt intervention: Consider discontinuation of adalimumab if significant hematologic abnormalities are confirmed 1

Clinical Decision Algorithm

When hematomas occur in patients on adalimumab:

1. Assess severity: Size, location, expansion rate, hemodynamic stability
2. Laboratory evaluation: Complete blood count with platelet count, coagulation studies
3. If thrombocytopenia or other cytopenias are present:
   • For mild cases: Close monitoring
   • For moderate-severe cases: Consider adalimumab discontinuation
   • For severe cases with significant bleeding: Hospitalization and supportive care

Prevention Strategies

To minimize risk of hematomas:

• Proper injection technique to reduce injection site hematomas
• Avoid concomitant use with other medications that increase bleeding risk when possible
• Patient education about signs of abnormal bleeding

Conclusion

While not among the most common side effects, hematomas can occur with adalimumab use primarily through its potential to cause thrombocytopenia and other hematologic abnormalities. The FDA label explicitly acknowledges this risk and recommends monitoring and potential discontinuation of therapy when significant hematologic abnormalities are confirmed.