Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pharmacologic stress testing uses vasodilators to provide objective evidence of myocardial ischemia. Adenosine and dipyridamole are nonselective adenosine receptor agonists that have been associated with myocardial infarction (MI) during intravenous infusion. Mechanisms postulated for this effect include coronary steal, transmural steal, global hypotension, and direct vasoconstriction. Regadenoson, a direct A2A agonist, was approved for use in stress testing in 2008. We describe a 68-year-old man who presented to our institution with typical angina, relieved by nitroglycerin. He did not have electrocardiogram (ECG) changes suggestive of myocardial pathology, and laboratory testing did not reveal a significant rise in troponin-I levels. To further assess the etiology of his symptoms, he underwent a pharmacologic stress test with regadenoson followed by technetium 99 m sestamibi. Six minutes after regadenoson infusion, the patient developed severe retrosternal chest pain accompanied by ST elevations on ECG. Sublingual nitroglycerin was administered that resolved both the pain and ECG changes. The patient subsequently underwent urgent coronary angiography and was found to have a 95% critical stenosis involving the left anterior descending artery. We conclude this case represents a MI secondary to coronary steal phenomenon induced by regadenoson infusion. Clinicians should be aware this adverse effect can occur despite the improved side-effect profile of regadenoson. Continuous monitoring of vital signs and the ECG with regular assessment of symptoms is imperative to identify this rare but potentially devastating adverse event.
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PMID:Acute myocardial infarction during regadenoson myocardial perfusion imaging. 2347 69

Adenosine receptors (ARs) function in the body's response to conditions of pathology and stress associated with a functional imbalance, such as in the supply and demand of energy/oxygen/nutrients. Extracellular adenosine concentrations vary widely to raise or lower the basal activation of four subtypes of ARs. Endogenous adenosine can correct an energy imbalance during hypoxia and other stress, for example, by slowing the heart rate by A1AR activation or increasing the blood supply to heart muscle by the A2AAR. Moreover, exogenous AR agonists, antagonists, or allosteric modulators can be applied for therapeutic benefit, and medicinal chemists working toward that goal have reported thousands of such agents. Thus, numerous clinical trials have ensued, using promising agents to modulate adenosinergic signaling, most of which have not succeeded. Currently, short-acting, parenteral agonists, adenosine and Regadenoson, are the only AR agonists approved for human use. However, new concepts and compounds are currently being developed and applied toward preclinical and clinical evaluation, and initial results are encouraging. This review focuses on key compounds as AR agonists and positive allosteric modulators (PAMs) for disease treatment or diagnosis. AR agonists for treating inflammation, pain, cancer, non-alcoholic steatohepatitis, angina, sickle cell disease, ischemic conditions and diabetes have been under development. Multiple clinical trials with two A3AR agonists are ongoing.
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PMID:Historical and Current Adenosine Receptor Agonists in Preclinical and Clinical Development. 3098 76