Management of Antiplatelet Therapy in Patients with Dizziness Pending Stroke Evaluation
Patients with dizziness who are on aspirin and clopidogrel should continue both medications until stroke is definitively ruled out, as premature discontinuation could increase the risk of stroke and associated morbidity and mortality.
Rationale for Continuing Antiplatelet Therapy
Antiplatelet therapy plays a critical role in preventing thrombotic events in patients at risk for stroke. The evidence strongly supports maintaining antiplatelet therapy during the diagnostic workup for several reasons:
Risk of Early Recurrent Events: Patients with suspected stroke or TIA are at highest risk for recurrent events in the first days to weeks after initial symptoms 1.
Established Benefit: The American College of Chest Physicians guidelines recommend long-term antiplatelet therapy for patients with history of ischemic stroke or TIA, with strong evidence (Grade 1A) supporting this practice 1.
Protection During Diagnostic Uncertainty: Until stroke is definitively ruled out, discontinuing antiplatelet therapy could place the patient at unnecessary risk of thrombotic events.
Specific Recommendations Based on Clinical Context
If Patient is Already on Dual Antiplatelet Therapy (DAPT):
- Continue both aspirin (75-100 mg daily) and clopidogrel (75 mg daily) until stroke is definitively ruled out 1, 2.
- If the patient has had a recent stroke or high-risk TIA within the past 21-90 days, DAPT provides additional protection against recurrent events compared to aspirin alone 3.
- The combination of aspirin and clopidogrel has shown a 20% relative risk reduction in cardiovascular death, MI, and stroke compared to placebo in high-risk patients 2.
If Patient is on Single Antiplatelet Therapy:
- Continue current antiplatelet therapy without interruption.
- For patients on aspirin alone, a loading dose of 160-325 mg should be considered if stroke is suspected and not yet ruled out 1.
After Stroke is Ruled Out:
- If stroke is ruled out and dizziness is determined to be from a non-vascular cause, antiplatelet therapy can be reconsidered based on the patient's other cardiovascular risk factors.
- If the patient has no other indications for DAPT, consider transitioning to single antiplatelet therapy, as prolonged DAPT carries an increased bleeding risk 4, 5.
Special Considerations
Bleeding Risk:
- Be aware that DAPT carries a higher bleeding risk compared to single antiplatelet therapy. The INSPIRES trial showed moderate-to-severe bleeding occurred in 0.9% of patients on clopidogrel-aspirin versus 0.4% on aspirin alone 3.
- Balance this risk against the benefit of stroke prevention, particularly in the acute diagnostic phase.
Dysphagia:
- If the patient has swallowing difficulties, aspirin can be administered rectally (325 mg daily) or via enteral tube (80 mg daily) 1, 6.
- Clopidogrel (75 mg daily) may be administered via enteral tube if necessary 6.
Timing Considerations:
- If stroke is confirmed and the patient received thrombolytic therapy, aspirin should be delayed until after the 24-hour post-thrombolysis scan has excluded intracranial hemorrhage 1.
Common Pitfalls to Avoid
Premature Discontinuation: Stopping antiplatelet therapy before stroke is ruled out may increase the risk of thrombotic events.
Ignoring Bleeding Risk: While continuing therapy is generally recommended, be vigilant for signs of bleeding, especially with DAPT.
Failure to Reassess: Once stroke is definitively ruled out, the need for DAPT should be reassessed based on the patient's overall cardiovascular risk profile.
Overlooking Alternative Diagnoses: While maintaining antiplatelet therapy, continue to investigate other causes of dizziness (vestibular, cardiac, metabolic, etc.).
By maintaining antiplatelet therapy until stroke is definitively ruled out, you maximize protection against potentially devastating thrombotic events while the diagnostic workup proceeds.