Share on Facebook Share on Twitter Email
Answers.com

adenosine

 
(ə-dĕn'ə-sēn') pronunciation
n.
A nucleoside, C10H13N5O4, composed of adenine linked to ribose, that is a structural component of nucleic acids and the major molecular component of ADP, AMP, and ATP.

[Blend of ADENINE and RIBOSE.]


Search unanswered questions...
Enter a question here...
Search: All sources Community Q&A Reference topics

A nucleoside comprising one adenine molecule linked to a D-ribose sugar molecule. The phosphate-ester derivatives of adenosine, AMP, ADP, and ATP, are of fundamental biological importance as carriers of chemical energy.




Adenosine



Drug Info:

Adenosine

Top

Brand names: Adeno-jec®, Adenocard®, Adenoscan®

Chemical formula:



Adenosine injection

What is adenosine injection?

ADENOSINE (Adenocard®) is an antiarrhythmic agent. Adenosine can help the heart to beat regularly when you have a particular type of rapid heartbeat called supraventricular tachycardia. It is not effective when a rapid heartbeat is caused by other problems. Generic adenosine injections are available.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
• asthma
• heart problems other than supraventricular tachycardia
• an unusual or allergic reaction to adenosine, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I use this medicine?

Adenosine is for injection into a vein. It is given by a health-care professional in a hospital or clinic setting.

Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.

What drug(s) may interact with adenosine?

caffeine
carbamazepine
dipyridamole
guarana
• theophylline

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What should I watch for while taking adenosine?

You may get dizzy; to reduce the risk of dizzy or fainting spells, do not sit or stand up quickly, especially if you are an older patient. Alcohol can make you more dizzy, increase flushing and rapid heartbeats. Avoid alcoholic drinks.

What side effects may I notice from receiving adenosine?

Side effects can be mild and temporary because the drug is active in the body only for a short time.
Side effects that you should report to your prescriber or health care professional as soon as possible:
• chest pain, palpitations
• difficulty breathing
• severe headache

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
• chest tightness
• dizziness, or lightheadedness
• flushing
• headache
• nausea, vomiting
• tingling in arms, numbness

Where can I keep my medicine?

Keep out of the reach of children.

Store between 15 and 30 degrees C (59 and 86 degrees F). Do not refrigerate. If crystals appear, warm to room temperature and only use if the solution is clear. Do not freeze. Throw away any unused portion.

Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.


A drug that is used for rapid restoration of normal heart rhythm and to help diagnose different types of arrhythmia. A prescription only drug in the form of a sterile solution for injection or infusion, it is available only for use in hospitals.

Side effects:
include transient flushing, chest pain, breathlessness, a choking sensation, nausea, and light-headedness.

Precautions:
adenosine should not be given to people with heart block, severe hypotension (low blood pressure), untreated heart failure, or chronic obstructive pulmonary disease. See also anti-arrhythmic drugs.

Interactions with other drugs:

Beta Blockers increase the risk of depression of heart function.
Dipyridamole enhances the effects of adenosine, therefore a reduction in the dose of adenosine is recommended if it is prescribed with dipyridamole.
Theophylline inhibits the action of adenosine.

Proprietary preparations:
Adenocor; Adenoscan.

See also anti-arrhythmic drugs.

Previous:adefovir dipivoxil, adapalene, adalimumab
Next:adjunct, adrenaline, adrenoceptors

Adenosine monophosphate, monosodium, or disodium adenylate - A nutraceutical that has been studied for its use in healing wounds, its treatment of diabetes mellitus, and its ability to lessen the affects of some instances of tachycardia (rapid heart racing, whose long lasting severity can cause death).


symbol: A or Ado; adenine riboside; 9-β-d-ribofuranosyladenine; a ribonucleoside found widely distributed in cells of every type as the free nucleoside and in combination in nucleic acids and various nucleoside coenzymes. It is a potent regulator of physiological transmission in both central and peripheral nervous systems, where it activates specific receptors (see adenosine receptor). It can inhibit or stimulate the release of a number of neurotransmitters, including acetylcholine, β-aminobutyrate, catecholamines, excitatory amino acids, and 5-hydroxytryptamine. The effect depends on whether the receptor involved inhibits adenylate cyclase (and thus inhibits release) or stimulates it.





Previous:adenoma, adenohypophysis, adeno+
Next:adenosine 3′,5′-phosphate, adenosine 3′-phosphate 5′-phosphosulfate, adenosine 5′-[α,β-methylene]diphosphate

One of the four bases that make up RNA and DNA containing the pentose sugar, 2-deoxy-d-ribose. Adenosine nucleotides are involved in the energy metabolism of all cells. Adenosine can be linked to a chain of one, two or three phosphate groups to form adenosine monophosphate (AMP), adenosine diphosphate (ADP) or adenosine triphosphate (ATP). The bond between the phosphate groups in ADP or the two bonds between the phosphate groups in ATP are called high-energy bonds because hydrolysis of a high-energy bond provides a large amount of free energy that can be used to drive other processes that would not otherwise occur spontaneously. The energy that is derived from the oxidation of carbohydrates, fats or proteins is used to synthesize ATP. The energy stored in ATP is then used directly or indirectly to drive all other cellular processes that require energy, of which there are four major types: (1) the transport of molecules and ions across cell membranes against concentration gradients, which maintains the internal environment of the cell and produces the membrane potential for the conduction of nerve impulses; (2) the contraction of muscle fibers and other fibers producing the motion of cells; (3) the synthesis of chemical compounds; (4) the synthesis of other high-energy compounds.

  • cyclic a. monophosphate (cyclic AMP, cAMP, 3′,5′-cAMP) — a cyclic nucleotide, adenosine 3′,5′-cyclic monophosphate, involved in the action of many hormones, including catecholamines, ACTH and vasopressin. The hormone (first message) binds to a specific β-receptor on the cell membrane of target cells. This activates an enzyme, adenylate cyclase, which produces cyclic AMP from ATP. Cyclic AMP acts as a second messenger activating other enzymes via covalent modulation within the cell.
  • a. deaminase — key enzyme in degradation pathway of adenosine; catalyzes the deamination of adenosine to inosine. Many cases of severe combined immunodeficiency syndrome in humans result from a heritable lack of adenosine deaminase.
  • a. diphosphate (ADP) — a nucleotide, adenosine 5′-pyrophosphate, produced by the hydrolysis of adenosine triphosphate (ATP). It is then converted back to ATP by oxidative, substrate or photosynthic phosphorylation. See also adp.
  • a. monophosphate (AMP) — a nucleotide, adenosine 5′-phosphate, involved in energy metabolism and nucleotide synthesis. Called also adenylic acid.
  • a. triphosphatase — a term used to refer to the enzymatic activity of certain intercellular processes that split ATP to form ADP and inorganic phosphate, when the energy released is not used for the synthesis of chemical compounds. Examples are the splitting of ATP in muscle contraction in myosin head-groups and the transport of ions across cell membranes. Called also ATPase.
  • a. triphosphatase test — used as a quantitative assay of the amount of avian leukosis virus in chicken tissues or tissue cultures. It depends on the virus's characteristic of carrying on its surface a phosphatase enzyme that dephosphorylates adenosine triphosphate.
  • a. triphosphate (ATP) — a nucleotide, adenosine 5′-triphosphate, occurring in all cells, where it stores energy in the form of high-energy phosphate bonds. Free energy of hydrolysis is supplied to drive metabolic reactions or to transport molecules against concentration gradients, when ATP is hydrolyzed to ADP and inorganic phosphate or to AMP and inorganic pyrophosphate. ATP is also used to produce high-energy phosphorylated intermediary metabolites, such as glucose-6-phosphate.

n

A compound derived from nucleic acid, composed of adenine and a sugar, D-ribose. Adenosine is the major molecular component of nucleotides and the nucleic acids.

Adenosine
Systematic (IUPAC) name
(2R,3R,4S,5R)-2-(6-amino-9H-purin-9-yl)-5-(hydroxymethyl)oxolane-3,4-diol
Clinical data
Trade names Adenocard
AHFS/Drugs.com monograph
Pregnancy cat. C
Legal status Australia - Legal; UK - Legal; US - Rx only
Routes Intravenous
Pharmacokinetic data
Bioavailability Rapidly cleared from circulation via cellular uptake
Protein binding No
Metabolism Rapidly converted to inosine and adenosine monophosphate
Half-life cleared plasma <30 seconds - half life <10 seconds
Excretion can leave cell intact or can be degraded to hypoxanthine, xanthine, and ultimately uric acid
Identifiers
CAS number 58-61-7 YesY
ATC code C01EB10
PubChem CID 60961
DrugBank DB00640
ChemSpider 54923 YesY
UNII K72T3FS567 YesY
KEGG C00212 YesY
ChEBI CHEBI:16335 YesY
ChEMBL CHEMBL477 N
Chemical data
Formula C10H13N5O4 
Mol. mass 267.241 g/mol
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Adenosine is a purine nucleoside comprising a molecule of adenine attached to a ribose sugar molecule (ribofuranose) moiety via a β-N9-glycosidic bond.

Adenosine plays an important role in biochemical processes, such as energy transfer—as adenosine triphosphate (ATP) and adenosine diphosphate (ADP)—as well as in signal transduction as cyclic adenosine monophosphate, cAMP. It is also an inhibitory neurotransmitter, believed to play a role in promoting sleep and suppressing arousal, with levels increasing with each hour an organism is awake.

Adenosine is often abbreviated Ado.

Contents

Pharmacological effects

Adenosine is an endogenous purine nucleoside that modulates many physiological processes. Cellular signaling by adenosine occurs through four known adenosine receptor subtypes (A1, A2A, A2B, and A3).[1]

Extracellular adenosine concentrations from normal cells are approximately 300 nM; however, in response to cellular damage (e.g. in inflammatory or ischemic tissue), these concentrations are quickly elevated (600–1,200 nM). Thus, in regard to stress or injury, the function of adenosine is primarily that of cytoprotection preventing tissue damage during instances of hypoxia, ischemia, and seizure activity. Activation of A2A receptors produces a constellation of responses that in general can be classified as anti-inflammatory.[citation needed]

Adenosine receptors

The different adenosine receptor subtypes (A1, A2A, A2B, and A3) are all seven transmembrane spanning G-protein coupled receptors. These four receptor subtypes are further classified based on their ability to either stimulate or inhibit adenylate cyclase activity. The A2A and A2B receptors couple to Gs and mediate the stimulation of adenylate cyclase, while the A1 and A3 adenosine receptors couple to Gi which inhibits adenylate cyclase activity. Additionally, A1 receptors couple to Go, which has been reported to mediate adenosine inhibition of Ca2+ conductance, whereas A2B and A3 receptors also couple to Gq and stimulate phospholipase activity.

Anti-inflammatory properties

Adenosine is believed to be an anti-inflammatory agent at the A(2A) receptor.[2][3] Topical treatment of adenosine to foot wounds in diabetes mellitus has been shown in lab animals to drastically increase tissue repair and reconstruction. Topical administration of adenosine for use in wound healing deficiencies and diabetes mellitus in humans is currently under clinical investigation.

Methotrexate's anti-inflammatory effect may be due to its stimulation of adenosine release.

Action on the heart

When administered intravenously, adenosine causes transient heart block in the Atrioventricular (AV) node. This is mediated via the A1 receptor, inhibiting adenylyl cyclase, reducing cAMP and so causing cell hyperpolarization by increasing outward K+ flux. It also causes endothelial dependent relaxation of smooth muscle as is found inside the artery walls. This causes dilation of the "normal" segments of arteries; i.e. where the endothelium is not separated from the tunica media by atherosclerotic plaque. This feature allows physicians to use adenosine to test for blockages in the coronary arteries, by exaggerating the difference between the normal and abnormal segments.

In individuals suspected of suffering from a supraventricular tachycardia (SVT), adenosine is used to help identify the rhythm. Certain SVTs can be successfully terminated with adenosine.[4] This includes any re-entrant arrhythmias that require the AV node for the re-entry, e.g., AV reentrant tachycardia (AVRT), AV nodal reentrant tachycardia (AVNRT). In addition, atrial tachycardia can sometimes be terminated with adenosine.

Adenosine has an indirect effect on atrial tissue causing a shortening of the refractory period. When administered via a central lumen catheter, adenosine has been shown to initiate atrial fibrillation because of its effect on atrial tissue. In individuals with accessory pathways, the onset of atrial fibrillation can lead to a life-threatening ventricular fibrillation.

Fast rhythms of the heart that are confined to the atria (e.g., atrial fibrillation, atrial flutter) or ventricles (e.g., monomorphic ventricular tachycardia) and do not involve the AV node as part of the re-entrant circuit are not typically converted by adenosine. However, the ventricular response rate is temporarily slowed with adenosine in such cases.

Because of the effects of adenosine on AV node-dependent SVTs, adenosine is considered a class IV antiarrhythmic agent. When adenosine is used to cardiovert an abnormal rhythm, it is normal for the heart to enter ventricular asystole for a few seconds. This can be disconcerting to a normally conscious patient, and is associated with angina-like sensations in the chest.[5]

Caffeine's principal mode of action is as an antagonist of adenosine receptors in the brain.

By nature of caffeine's purine structure[6] it binds to some of the same receptors as adenosine.[6] The pharmacological effects of adenosine may therefore be blunted in individuals who are taking large quantities of methylxanthines (e.g., caffeine, found in coffee and tea, or theobromine, as found in chocolate). [7][citation needed]

Action in the central nervous system

Generalized, adenosine has an inhibitory effect in the central nervous system (CNS). Caffeine's stimulatory effects, on the other hand, are primarily (although not entirely) credited to its inhibition of adenosine by binding to the same receptors, and therefore effectively blocking adenosine receptors in the CNS. This reduction in adenosine activity leads to increased activity of the neurotransmitters dopamine and glutamate.

Dosage

When given for the evaluation or treatment of a supraventricular tachycardia (SVT), the initial dose is 6 mg, given as a rapid parenteral infusion. Due to adenosine's extremely short half-life, the IV line is started as proximal (near) to the heart as possible, such as the cubital fossa. The IV push is often followed with an immediate flush of 10-20ccs of saline. If this has no effect (i.e. no evidence of transient AV block), a 12 mg dose can be given 1–2 minutes after the first dose. AHA 2010 IS NO LONGER RECOMMENDING A SECOND DOSE OF 12MG. PLEASE VIEW ALGORITHM AS CONFIRMATION.[citation needed] Some clinicians may prefer to administer a higher dose (typically 18 mg), rather than repeat a dose that apparently had no effect.[dubious ] When given to dilate the arteries, such as in a "stress test", the dosage is typically 0.14 mg/kg/min, administered for 4 or 6 minutes, depending on the protocol.

The recommended dose may be increased in patients on theophylline since methylxanthines prevent binding of adenosine at receptor sites. The dose is often decreased in patients on dipyridamole (Persantine) and diazepam (Valium) because adenosine potentiates the effects of these drugs. The recommended dose is also reduced by half in patients who are presenting congestive heart failure, myocardial infarction, shock, hypoxia, and/or hepatic or renal insufficiency, and in elderly patients.

Drug interactions

Dopamine may precipitate toxicity in the patient. Carbamazepine may increase heart block. Theophylline and caffeine (methylxanthines) competitively antagonize adenosine's effects; an increased dose of adenosine may be required. Dipyridamole potentiates the action of adenosine, requiring the use of lower doses.

Contraindications

Common Contraindications for adenosine are:

  • 2nd or 3rd degree heart block (without a pacemaker)
  • Sick sinus syndrome (without a pacemaker)
  • Long QT syndrome
  • Severe hypotension
  • Decompensated heart failure
  • Asthma, traditionally an absolute CI this is being contended and it is now considered relative (however, selective adenosine agonists are being investigated for use in treatment of asthma)[8]
  • Poison/drug-induced tachycardia

In Wolff-Parkinson-White syndrome, adenosine may be administered if equipment for cardioversion is immediately available as a backup.

Side effects

Many individuals experience facial flushing, a temporary rash on the chest, lightheadedness, diaphoresis, or nausea after administration of adenosine due to its vasodilatory effects. Metallic taste is a hallmark side effect of adenosine administration. These symptoms are transitory, usually lasting less than one minute. It is classically associated with a sense of "impending doom", more prosaically described as apprehension. This lasts a few seconds after administration of a bolus dose, during transient asystole induced by intravenous administration. In some cases adenosine can make patients' limbs feel numb for about 2–5 minutes after administration intravenously depending on the dosage (usually above 12 mg).

Metabolism

Adenosine used as a second messenger can be the result of de novo purine biosynthesis via adenosine monophosphate (AMP), though it is possible other pathways exist.[9]

When adenosine enters the circulation, it is broken down by adenosine deaminase, which is present in red cells and the vessel wall.

Dipyridamole, an inhibitor of adenosine deaminase, allows adenosine to accumulate in the blood stream. This causes an increase in coronary vasodilatation.

Adenosine deaminase deficiency is a known cause of immunodeficiency.

Analogs and viruses

The adenosine analog, NITD008 has been reported to directly inhibit the recombinant an RNA-dependent RNA polymerase of the dengue virus by terminating its RNA chain synthesis. This suppresses peak viremia, rise in cytokines and prevented infected animal from death raising the possibility of a new treatment for this flavivirus.[10] The 7-deaza-adenosine analog has been shown to inhibit the replication of the hepatitis C virus.[11] Such adenosine analogs are potentially clinically useful since they can be taken orally.

See also

References

  1. ^ Haskó G, Linden J, Cronstein B, Pacher P (September 2008). "Adenosine receptors: therapeutic aspects for inflammatory and immune diseases". Nat Rev Drug Discov 7 (9): 759–70. doi:10.1038/nrd2638. PMC 2568887. PMID 18758473. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2568887. 
  2. ^ Nakav S, Chaimovitz C, Sufaro Y (2008). Bozza, Patricia. ed. "Anti-Inflammatory Preconditioning by Agonists of Adenosine A1 Receptor". PLoS ONE 3 (5): e2107. doi:10.1371/journal.pone.0002107. PMC 2329854. PMID 18461129. http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002107. 
  3. ^ Trevethick MA, Mantell SJ, Stuart EF, Barnard A, Wright KN, Yeadon M (October 2008). "Treating lung inflammation with agonists of the adenosine A2A receptor: promises, problems and potential solutions". Br. J. Pharmacol. 155 (4): 463–74. doi:10.1038/bjp.2008.329. PMC 2579671. PMID 18846036. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2579671. 
  4. ^ Mitchell J, Lazarenko G (November 2008). "Wide QRS complex tachycardia. Diagnosis: Supraventricular tachycardia with aberrant conduction; intravenous (IV) adenosine". CJEM 10 (6): 572–3, 581. PMID 19000353. http://caep.ca/template.asp?id=563f5c92af544619b2ac53fbba2ce6c5. 
  5. ^ Pijls, Nico H. J.; Bernard De Bruyne (2000). Coronary Pressure. Springer. ISBN 0-7923-6170-9. 
  6. ^ a b "Caffeine". Chemistry Explained. http://www.chemistryexplained.com/Bo-Ce/Caffeine.html. 
  7. ^ "Vitamin B4". R&S Pharmchem. April 2011. http://www.rspharmchem.com/vitamin-b4.htm. 
  8. ^ Brown RA, Spina D, Page CP (March 2008). "Adenosine receptors and asthma". Br. J. Pharmacol. 153 Suppl 1 (S1): S446–56. doi:10.1038/bjp.2008.22. PMC 2268070. PMID 18311158. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2268070. 
  9. ^ Miller-Patrick K, Vincent DL, Early RJ, et al. (1993). "Effects of the purine biosynthesis pathway inhibitors azaserine, hadacidin, and mycophenolic acid on the developing ovine corpus luteum". Chin J Physiol 36 (4): 245–52. PMID 8020339. 
  10. ^ Yin Z, Chen YL, Schul W, Wang QY, Gu F, Duraiswamy J, Reddy Kondreddi R, Niyomrattanakit P, Lakshminarayana SB, Goh A, Xu HY, Liu W, Liu B, Lim JY, Ng CY, Qing M, Lim CC, Yip A, Wang G, Chan WL, Tan HP, Lin K, Zhang B, Zou G, Bernard KA, Garrett C, Beltz K, Dong M, Weaver M, He H, Pichota A, Dartois V, Keller TH, Shi PY. (2009). Proc Natl Acad Sci U S A. 106: 20435–20439 doi:10.1073/pnas.0907010106 PMID 19918064
  11. ^ Olsen, DB; Eldrup, AB; Bartholomew, L; Bhat, B; Bosserman, MR; Ceccacci, A; Colwell, LF; Fay, JF et al. (2004). "A 7-Deaza-Adenosine Analog Is a Potent and Selective Inhibitor of Hepatitis C Virus Replication with Excellent Pharmacokinetic Properties". Antimicrobial agents and chemotherapy 48 (10): 3944–53. doi:10.1128/AAC.48.10.3944-3953.2004. PMC 521892. PMID 15388457. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=521892. 

External links


 
 

 

Copyrights:

American Heritage Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
Oxford Dictionary of Chemistry. A Dictionary of Chemistry. Sixth Edition. Copyright © Market House Books Ltd, 2008. All rights reserved.  Read more
Drug Info. Gold Standard. Copyright © 2008 by Gold Standard. All rights reserved.  Read more
 Oxford A-Z of Medicinal Drugs. Market University Press. © 2000, 2003, 2010 An A-Z of Medicinal Drugs. All rights reserved.  Read more
Wiley Dictionary of Flavors. Copyright © 2008 by Wiley-Blackwell. Wiley and the Wiley logo are registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries. Used here by license.  Read more
 Oxford Dictionary of Biochemistry. Oxford University Press. Oxford Dictionary of Biochemistry and Molecular Biology © 1997, 2000, 2006 All rights reserved.  Read more
Saunders Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.  Read more
Mosby's Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.  Read more
Wikipedia on Answers.com. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article Adenosine Read more

Follow us
Facebook Twitter
YouTube