Do I need to be NPO (nil per os) for a Lexiscan (regadenoson) stress test?

NPO Requirements for Lexiscan Stress Test

You do not need to be NPO (nil per os) for a Lexiscan (regadenoson) stress test.

Understanding Lexiscan (Regadenoson) Stress Testing

Lexiscan is a pharmacological stress agent used when patients cannot adequately exercise during cardiac stress testing. As a selective adenosine A2A receptor agonist, it causes coronary vasodilation, which helps identify coronary artery disease during myocardial perfusion imaging.

NPO Status and Preparation Guidelines

Unlike some other medical procedures that require fasting, Lexiscan stress tests do not have specific NPO requirements in the medical guidelines. The guidelines for pharmacological stress testing focus on:

• Contraindications to vasodilator administration
• Patient safety monitoring
• Appropriate patient selection

Caffeine Restriction

While you don't need to be completely NPO, there is one important dietary restriction:

• Avoid caffeine for at least 12 hours before the test 1
  • This includes coffee, tea, chocolate, energy drinks, and caffeine-containing medications
  • Caffeine is a methylxanthine that can interfere with the vasodilatory effects of regadenoson

Medication Considerations

Some medications may need to be temporarily discontinued:

• Dipyridamole-containing medications should be stopped before the test
• Aminophylline should be avoided within 12 hours of the test 1

Safety Profile of Lexiscan

Regadenoson is generally well-tolerated with a favorable safety profile:

• Most adverse events begin soon after administration and resolve within approximately 15 minutes 2
• Common side effects include dyspnea (shortness of breath), chest discomfort, and headache 3
• Hemodynamic changes typically include a mild increase in heart rate and minimal changes in blood pressure 4

Special Populations

Lexiscan has been studied in various patient populations with good safety outcomes:

• Patients with pulmonary hypertension 5
• Patients with end-stage liver disease 4
• Patients undergoing cardiac MRI 3

Practical Recommendations

1. Maintain normal food intake before the test (no fasting required)
2. Stay well-hydrated before the procedure
3. Avoid caffeine for at least 12 hours before the test
4. Take your regular medications unless specifically instructed otherwise by your healthcare provider
5. Inform your provider about all medications you're taking, especially those containing dipyridamole or aminophylline

By following these guidelines, you can ensure the most accurate results from your Lexiscan stress test while maintaining your comfort and safety.