Is it okay to give Imitrex (sumatriptan) before a Lexiscan (regadenoson) stress test?

Sumatriptan Administration Before Lexiscan Stress Testing

No, sumatriptan (Imitrex) should not be given before a Lexiscan (regadenoson) stress test due to the risk of coronary vasospasm and the potential for masking or confounding cardiac ischemia assessment.

Primary Cardiovascular Concerns

The FDA explicitly warns that sumatriptan can cause coronary artery vasospasm (Prinzmetal's angina), even in patients without a history of CAD, and has been associated with myocardial ischemia and infarction occurring within hours of administration 1. This vasoconstrictive effect directly conflicts with the purpose of a Lexiscan stress test, which is designed to detect coronary artery disease through vasodilation and assessment of myocardial perfusion.

Mechanism of Interference

• Sumatriptan causes vasoconstriction of cranial and potentially coronary blood vessels through 5-HT1B/1D receptor agonism 2
• Research demonstrates that sumatriptan reduces oxygen delivery to peripheral skeletal muscle through mild vasoconstriction, with effects lasting 5-20 minutes post-injection and potentially longer 3
• This vasoconstrictive effect could create "balanced ischemia" that may not be detected on stress testing, as documented in cases where significant coronary lesions were missed on regadenoson stress tests 4

Specific Cardiovascular Side Effects

Sumatriptan commonly causes cardiovascular symptoms that overlap with cardiac ischemia:

• Chest pressure, tightness, and heaviness occur in 3-5% of patients 5
• These sensations typically affect the precordium, throat, neck, and jaw 1
• While usually non-cardiac in origin, the FDA mandates cardiac evaluation in high-risk patients experiencing these symptoms 1

Timing Considerations

If sumatriptan has already been administered:

• Delay the stress test until the drug's effects have dissipated
• Sumatriptan has a half-life of approximately 2 hours 2
• Allow at least 12-24 hours after sumatriptan administration before proceeding with cardiac stress testing to ensure complete drug clearance and resolution of vasoconstrictive effects

Clinical Pitfalls to Avoid

• Do not assume chest symptoms are migraine-related in patients scheduled for cardiac evaluation—the FDA warns against administering sumatriptan when symptoms may represent actual cardiac ischemia 1
• Patients with multiple cardiovascular risk factors (increased age, diabetes, hypertension, smoking, obesity, strong family history of CAD) require cardiovascular evaluation before ever receiving sumatriptan 1
• The presence of uncontrolled hypertension is an absolute contraindication to sumatriptan use 6

Alternative Management

For patients with migraine requiring stress testing:

• Treat the migraine with non-vasoconstrictive agents such as acetaminophen or NSAIDs before the procedure 6
• Ensure adequate hydration, which is important for optimal stress test performance 7
• Schedule the stress test when the patient is migraine-free if possible