Adenosine is a nucleoside. It occurs in all living tissues as Nucleotides. It combines with phosphate to form Adenosine Monophosphate ( AMP ) and Adenosine Triphosphate ( ATP ).
It is an important component of DNA and RNA. It is involved in physiologic processes such as Energy transfer and Signal Transduction.

Functions of Adenosine in the Body
In Brain
Adenosine acts as an Inhibitory Neurotransmitter in the Brain. It works as a Central Nervous System depressant and induces sleep.
In Heart
It dilates the coronary arteries and is used in Adenosine Thallium scan of the Heart.
It is effective for treating Arrhythmia. It regulates Heart rate by slowing down the electrical conduction in heart.
Intravenous ATP is used in the treatment of Non-small-lung cancer. Intramuscular AMP helps to relieve symptoms caused due to Venous Stasis Ulcers.
In Lungs
It causes constriction in the Airways and decreases the blood flow resistance in the lungs. It is thus useful in reducing the Pulmonary Artery Pressure.
In Liver
It constricts the Blood Vessels and increases the breakdown of Glycogen to form Glucose. It prevents the fat breakdown and improves uptake of glucose.

Action of Adenosine
Vasodilation, Anti Arrhythmia, Analgesia

Benefits of Adenosine in the Body
It regulates the blood flow in the Brain tissues.
It is used to treat Nerve Pain and Pulmonary Hypertension.
It is used to treat Surgical Pain and control Blood Pressure during Anesthesia, Heart Tests before Surgery.
It treats Arrhythmia and normalizes heart rhythm.
It raises the secretions in Adrenal glands and production of Steroid hormones.

Side Effects of Adenosine in the Body
Consult with your Physician if any of these side effects occur:
Low blood pressure
Headache, Dizziness, Light-Headedness
Flushing, Nausea
Stomach Pain
Some less common allergic reactions can also occur like
Difficulty In Breathing
Throat, Neck Or Jaw Pain
Fast, Slow Or Irregular Heartbeat
Speech Or Vision Problem
Tightness In Chest Or Throat
Chest Pain
Swelling Of The Mouth, Face, Lips Or Tongue
Fainting, Hives Or Itching

DO NOT USE
Avoid use if
You are allergic to any ingredient in Adenosine.
If you are having Sinus Node disease.
If you have any Cardiac Arrest history.
If you have Asthma or any other breathing problem.
If you are pregnant, or planning to become pregnant or Breast feeding.
If you have any medicine or food allergy.
If you have a history of Seizures.
Avoid food or drink having caffeine before taking Adenosine.
There may be some contradictory reactions with Adenosine. Consult your doctor before, if any of the above applies to you.

Note:
It is given as an injection by doctor at a hospital or clinic. It cannot be stored at home.
It is recommended to have Adenosine with the consent of doctor if you are pregnant. Consult your health care provider for any questions about exact dosing and usage.