LEXISCAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LEXISCAN (LEXISCAN).
Regadenoson is a low-affinity agonist for the A2A adenosine receptor, with lower affinity for the A1 receptor. Activation of the A2A receptor on coronary vascular smooth muscle causes coronary vasodilation and increases coronary blood flow, allowing detection of coronary artery disease during myocardial perfusion imaging.
| Metabolism | Regadenoson is not metabolized by CYP450 enzymes; it is excreted unchanged primarily in the urine (approximately 57% as parent drug). |
| Excretion | Primarily renal (60-80% unchanged); minor biliary/fecal (20-40%) |
| Half-life | Terminal half-life 1.2-3.2 hours (mean 2.0 h); clinically, clearance is rapid, allowing repeat dosing within 3-5 half-lives |
| Protein binding | <10% (primarily albumin) |
| Volume of Distribution | 0.3-0.9 L/kg (mean 0.6 L/kg); indicates distribution mainly into extracellular fluid |
| Bioavailability | IV only (100% bioavailability); oral bioavailability negligible (<2%) due to first-pass metabolism |
| Onset of Action | IV: 0-2 minutes (immediate coronary vasodilation); peak effect within 1-2 minutes |
| Duration of Action | IV: 6-10 minutes (coronary hyperemia); clinical effect persists for the duration of imaging (10-20 minutes) |
0.4 mg intravenously as a single bolus over 10 to 60 seconds.
| Dosage form | SOLUTION |
| Renal impairment | No dosage adjustment required for renal impairment. Regadenoson is minimally renally eliminated. |
| Liver impairment | No dosage adjustment required for mild to moderate hepatic impairment (Child-Pugh class A and B). Not studied in severe hepatic impairment (Child-Pugh class C); use with caution. |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dosage adjustment recommended in elderly patients. Clinical studies included patients aged 65 and older, with no overall differences in safety or efficacy observed. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LEXISCAN (LEXISCAN).
| Breastfeeding | Unknown if regadenoson is excreted in human milk. No M/P ratio available. Caution advised; discontinue nursing or drug, considering importance of drug to mother. |
| Teratogenic Risk | Pregnancy Category C. Animal studies have shown adverse effects (increased fetal resorptions) but no human studies exist. Regadenoson is an adenosine A2A receptor agonist; fetal risk cannot be ruled out. Use only if clearly needed, weighing benefit against potential risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
Risk of fatal cardiac arrest, myocardial infarction, and ventricular arrhythmias. Resuscitative equipment and trained personnel must be available before and during administration. Do not use in patients with unstable angina or cardiovascular instability.
| Serious Effects |
["Known bronchoconstrictive or bronchospastic lung disease (e.g., asthma, COPD)","Unstable angina or cardiovascular instability (including recent myocardial infarction, severe hypotension, or uncontrolled hypertension)","Hypersensitivity to regadenoson or any component of the formulation"]
| Precautions | ["Cardiac events: Myocardial ischemia, infarction, cardiac arrest, ventricular arrhythmias","Seizures: May lower seizure threshold; use cautiously in patients with history of seizures","Bronchoconstriction: Contraindicated in patients with known bronchoconstrictive or bronchospastic lung disease (e.g., asthma, COPD) due to risk of respiratory arrest","Hypotension: May cause significant hypotension; monitor blood pressure","Atrial fibrillation/flutter: Can induce new or recurrent arrhythmias","Sinoatrial and atrioventricular nodal block: Can cause transient heart block"] |
| Food/Dietary |
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| Monitor maternal heart rate, blood pressure, and ECG continuously. Observe for signs of myocardial ischemia, bronchospasm, and seizure. In pregnancy, assess fetal heart rate if appropriate. |
| Fertility Effects | No human data on fertility effects. In animal studies, no impairment of fertility was observed at doses up to 20 times the MRHD. |
| Avoid caffeine-containing foods and beverages (coffee, tea, cola, chocolate, energy drinks) for at least 12 hours before administration. Caffeine is a competitive antagonist of the adenosine A2A receptor and can reduce the diagnostic efficacy of regadenoson by blunting hyperemic response. Theophylline and other methylxanthines in food or drugs should also be avoided. |
| Clinical Pearls | Do not administer LEXISCAN (regadenoson) to patients with signs or symptoms of unstable angina or cardiovascular instability. For patients at risk of seizures, weigh risks due to potential for convulsions. Have emergency resuscitative equipment immediately available. Avoid concurrent use of methylxanthines (e.g., caffeine, theophylline) as they are adenosine receptor antagonists and may reduce efficacy. Aminophylline can be used to terminate severe adverse reactions. |
| Patient Advice | Inform your healthcare provider if you have a history of seizures, heart problems (especially unstable angina), or asthma/COPD. · Do not eat or drink anything containing caffeine (coffee, tea, chocolate, soda) for at least 12 hours before your stress test. · You may experience shortness of breath, chest discomfort, headache, dizziness, or nausea during the procedure – these usually resolve quickly. · Tell your doctor immediately if you develop chest pain, severe breathing difficulty, or convulsions. · You will be monitored closely during and after the injection. Do not drive until you are fully recovered. |