Adenosine 3mg Injection is an anti-arrhythmic medicine used to treat life-threatening arrhythmia (abnormal heart rhythm). It restores normal heart rhythm by blocking abnormal electrical signals in the heart. Adenosine 3mg Injection is also used to carry out diagnostic stress tests of the heart. It is administered under the supervision of a doctor. Your doctor will decide the dose and duration of the medicine for you. The doctor may closely monitor your blood pressure, heart rate, and ECG until you become stable. You should continue all your other medicines that are advised by the doctor for your long-term treatment even after this injection. Common side effects of this medicine include flushing (sense of warmth in the face, ears, neck, and trunk), headache, chest pain, dizziness, and nausea. Consult your doctor if these effects bother you. This medicine is used with caution for some people. Thus, you must inform the doctor if you are suffering from any kidney or liver disease. Also, let your doctor know if you are pregnant or breastfeeding and about all the other medications that you are taking regularly.