Can a patient with Alzheimer's disease undergoing Donanemab (aducanumab) therapy have surgery?

Can a Patient Have Surgery While on Donanemab?

Yes, patients on donanemab can undergo surgery, but the timing and management depend on the surgery type and bleeding risk, as there are no specific perioperative guidelines for this monoclonal antibody class.

Key Principle: Donanemab is Not an Anticoagulant

• Donanemab is an IgG1 monoclonal antibody targeting aggregated amyloid-beta plaques in Alzheimer's disease, not an anticoagulant or immunosuppressant that requires specific perioperative interruption 1, 2
• The drug has an elimination half-life of approximately 9.3 days (range 5.6-16.2 days), which is relevant for pharmacokinetic considerations but does not create direct bleeding risk 1
• Unlike anticoagulants (warfarin, DOACs) or certain biologics used in rheumatic diseases, there are no published perioperative management guidelines specific to anti-amyloid monoclonal antibodies 3

Primary Safety Concern: ARIA (Amyloid-Related Imaging Abnormalities)

The main perioperative consideration is the risk of ARIA-E (vasogenic cerebral edema) and ARIA-H (microhemorrhages), which occur most commonly in the first 6 months of treatment:

• ARIA-E occurred in approximately 20% of donanemab-treated patients, with most events occurring early in treatment 1, 4
• Cerebral microhemorrhages occurred in 13% of patients and superficial siderosis in 4% of patients receiving donanemab 1
• These risks are highest during the initial treatment phase and decline after 6 months of therapy 4, 5

Surgical Risk Stratification

For Neurosurgical or High-Risk Intracranial Procedures:

• Defer elective neurosurgery if possible during the first 6 months of donanemab therapy when ARIA risk is highest 1, 4
• Obtain baseline and recent brain MRI (within 2-4 weeks) before any neurosurgical procedure to assess for asymptomatic ARIA 4
• If ARIA-E or significant ARIA-H is present on pre-surgical imaging, postpone elective surgery until resolution is confirmed 1, 4
• For emergency neurosurgery, proceed with heightened awareness of potential cerebral edema or microhemorrhages, but donanemab does not require reversal like anticoagulants 3

For Non-Neurosurgical Procedures:

• Proceed with surgery without interrupting donanemab for most elective procedures including orthopedic, abdominal, cardiac, and vascular surgery 3
• Standard perioperative prophylaxis and hemostasis protocols apply, as donanemab does not increase systemic bleeding risk 1
• No specific "washout period" is required, unlike biologics used in rheumatoid arthritis where surgery is timed to the end of dosing cycles 3

Practical Management Algorithm

Step 1: Assess Surgery Urgency and Type

• Emergency surgery (within 6 hours): Proceed immediately; donanemab does not require reversal 3
• Urgent surgery (6-24 hours): Proceed with standard protocols 3
• Elective surgery: Consider timing relative to treatment duration and ARIA risk 4

Step 2: Evaluate ARIA Status

• For neurosurgical procedures: Obtain brain MRI within 2-4 weeks of planned surgery 4
• If ARIA-E present: Defer elective surgery until resolution 1, 4
• If no ARIA: Proceed with surgery 4

Step 3: Perioperative Continuation

• Continue donanemab through the perioperative period for non-neurosurgical procedures 3
• Donanemab infusions are given every 4 weeks; minor schedule adjustments around surgery are acceptable 1
• Resume regular dosing schedule postoperatively once patient is stable 1

Critical Distinctions from Other Medications

Donanemab differs fundamentally from medications requiring perioperative interruption:

• Unlike anticoagulants (dabigatran, rivaroxaban, apixaban), donanemab does not affect coagulation and requires no preoperative discontinuation based on half-lives 3, 6, 7
• Unlike anti-TNF biologics in rheumatoid arthritis, there is no evidence linking donanemab to increased surgical site infections or wound complications 3
• Unlike corticosteroids, donanemab does not impair wound healing or increase infection risk (OR for steroids: 1.68 for infectious complications) 3
• Unlike immunomodulators (azathioprine, methotrexate), donanemab can be continued without concern for postoperative complications 3

Common Pitfalls to Avoid

• Do not treat donanemab like an anticoagulant requiring preoperative discontinuation or reversal agents 3
• Do not assume increased systemic bleeding risk from donanemab; ARIA-H represents localized cerebral microhemorrhages, not systemic coagulopathy 1, 5
• Do not delay necessary surgery in stable patients beyond 6 months of treatment when ARIA risk has substantially declined 4
• Do not proceed with elective neurosurgery without recent brain MRI to exclude active ARIA 1, 4

Special Populations

Patients with multiple comorbidities:

• Donanemab trial participants had comorbidity profiles consistent with Medicare populations, suggesting safety across diverse clinical settings 4
• Co-medications in trials reflected real-world polypharmacy, with no specific drug interactions requiring perioperative adjustment 4

Patients requiring anticoagulation for other indications:

• Manage concurrent anticoagulation (for atrial fibrillation, VTE) according to standard perioperative anticoagulation guidelines 3, 6, 7
• Donanemab does not add to anticoagulant-related bleeding risk 1