What are alternatives to aspirin (acetylsalicylic acid) for dual antiplatelet therapy in brain aneurysm stenting treatment for a patient with a true allergy to aspirin?

Alternatives to Aspirin for Dual Antiplatelet Therapy in Brain Aneurysm Stenting

For patients with true aspirin allergy requiring dual antiplatelet therapy for brain aneurysm stenting, ticagrelor is the preferred alternative to aspirin and should be used in combination with clopidogrel. 1

Primary Options for Aspirin-Allergic Patients

When aspirin cannot be used due to true allergy, the following alternatives are recommended:

First-line Option:

• Ticagrelor (90 mg twice daily) 1, 2
  • Provides consistent platelet inhibition
  • Does not require activation like clopidogrel
  • FDA-approved for reducing stroke risk in patients with acute ischemic stroke or TIA 2
  • Has shown efficacy and safety in neuroendovascular procedures 3, 4

Second-line Option:

• Clopidogrel (75 mg daily) 1
  • Long-established alternative to aspirin
  • May have variable response with 4-50% of patients being non-responders 4
  • Consider platelet function testing to ensure adequate response

Dosing Recommendations

For brain aneurysm stenting:

• Ticagrelor: Loading dose of 180 mg, followed by 90 mg twice daily 2
• Clopidogrel: Loading dose of 300-600 mg, followed by 75 mg daily 1

Duration of Therapy

• For stent placement: Dual antiplatelet therapy should be continued for at least 3-6 months after stent placement, depending on the type of stent used 1
• After initial period: Consider continuing single antiplatelet therapy indefinitely 1

Monitoring and Safety Considerations

1. Bleeding Risk Assessment:

   • Monitor for signs of bleeding, particularly in the first few weeks
   • Consider reducing heparin dosing during the procedure to 50 U/kg rather than 70 U/kg to reduce hemorrhagic complications 4

2. Medication Interactions:

   • Avoid strong CYP3A inhibitors or inducers with ticagrelor 2
   • Monitor for drug interactions, especially with statins 2

3. Timing Around Procedures:

   • If possible, discontinue ticagrelor at least 5 days before any surgery 1
   • For clopidogrel, discontinue at least 7 days before surgery if possible 1

Special Considerations

• Clopidogrel Resistance: If using clopidogrel, consider platelet function testing to identify non-responders
• High Bleeding Risk: In patients with higher bleeding risk, consider cilostazol as a potential alternative, though evidence is more limited in neurovascular procedures 5
• Pre-procedure Planning: Start dual antiplatelet therapy at least 5-7 days before elective stenting procedures to achieve adequate platelet inhibition

Pitfalls to Avoid

1. Do not use two P2Y12 inhibitors together (e.g., clopidogrel plus ticagrelor) as there are no data supporting this approach and it is not recommended 1

2. Do not assume all patients respond adequately to clopidogrel; consider platelet function testing or use ticagrelor which has more predictable effects

3. Do not discontinue antiplatelet therapy prematurely after stenting, as this significantly increases the risk of stent thrombosis

4. Do not use standard aspirin desensitization protocols without specialist consultation in patients with true aspirin allergy undergoing urgent procedures

The evidence strongly supports that patients with true aspirin allergy can safely and effectively receive alternative antiplatelet therapy with either ticagrelor or clopidogrel for brain aneurysm stenting procedures.