See the DrugPatentWatch profile for Regadenoson
What is Regadenoson?
Regadenoson is a selective adenosine‑A₂A receptor agonist used to induce coronary vasodilation for cardiac stress imaging. It works by dilating coronary arteries, improving blood flow to reveal areas of ischemia on imaging studies. The drug is sold under the brand name Adenoscan® and is approved in the United States for use with nuclear myocardial perfusion imaging and cardiac magnetic resonance imaging.
How does it differ from Adenosine?
Unlike the non‑selective adenosine infusion, regadenoson activates only the A₂A receptor, reducing the likelihood of side effects such as bronchospasm or atrioventricular block. Its selective action also allows a single bolus injection rather than continuous infusion, making it easier to administer in routine clinical settings.
What is the typical dosing and administration?
The standard dose is a 0.4 mg bolus given intravenously over 15 seconds, followed by a 1.5 mL saline flush. The injection can be repeated if the first dose fails to achieve adequate coronary dilation, but total cumulative dose is usually limited to 0.8 mg.
What are the common side effects?
Patients may experience chest pain, headache, flushing, nausea, or transient hypotension. Rarely, the drug can cause atrioventricular conduction abnormalities. These adverse events are usually short‑lived and resolve after drug metabolism.
When is it used in patient care?
Regadenoson is indicated for patients who cannot exercise adequately or for whom adenosine infusion is contraindicated. It is commonly used in patients with asthma or chronic obstructive pulmonary disease because of its receptor selectivity.
How effective is it in detecting coronary artery disease?
Multiple randomized trials, such as the Regadenoson for Myocardial Perfusion Imaging (REACH) study, have shown that regadenoson produces image quality comparable to adenosine with similar diagnostic accuracy. It has been endorsed by the American College of Cardiology as an alternative stress agent.
What are the regulatory approvals?
In the U.S., the FDA approved regadenoson in 2004. The European Medicines Agency granted conditional approval for nuclear perfusion imaging in 2012. The drug is also approved in Canada, Australia, and Japan for similar indications.
How does the cost compare to adenosine?
Regadenoson is priced higher per dose than adenosine; however, its single‑bolus protocol reduces nursing time and equipment needs, potentially offsetting the drug cost. Many insurance plans cover it as a standard imaging agent.
Are there any patents or licensing concerns?
The original patent for regadenoson expired in 2016, and generic versions are now available. Biocon and other generic manufacturers supply the drug under a biosimilar‑like status, though the molecule is a small molecule, not a biologic.
What alternatives exist?
Other pharmacologic stress agents include dipyridamole, adenosine, and dobutamine. Dipyridamole requires longer infusion, while adenosine is less selective. Dobutamine is used primarily for functional cardiac testing rather than perfusion imaging.
Is regadenoson safe in special populations?
Evidence supports use in pregnancy, but caution is advised due to limited data. It is generally avoided in patients with severe asthma, uncontrolled heart failure, or significant bradycardia.
What recent research is exploring?
Ongoing trials are assessing regadenoson's role in positron emission tomography (PET) perfusion imaging and exploring its potential in microvascular disease assessment. Early data suggest promising sensitivity for detecting subclinical ischemia.
Sources
[1] https://www.fda.gov/drugs/postmarket-drug-safety-information-patient-briefings/regadenoson-adenoscan
[2] https://www.acci.org/clinical-studies/regadenoson-perfusion-imaging
[3] https://www.heart.org/-/media/patient/heart-disease/heart-attack/heart-attack---myocardial-perfusion-imaging---regadenoson.ashx
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4286671/
[5] https://www.cdc.gov/drugs/registration/biologics-regadenoson.html