Adenosine (Adenocard) is an FDA-approved drug, primarily used to treat irregular heartbeat (arrhythmias), in addition to pain and high blood pressure in the lungs (pulmonary hypertension). Read on to understand its uses, mechanism of action, and side effects.
Disclaimer: By writing this post, we are not recommending this drug. Some of our readers requested that we commission a post on it, and we are simply providing information that is available in the clinical and scientific literature. Please discuss your medications with your doctor.
If you are interested in the role of the adenosine naturally produced in the body and its brain- and immune-related pathways, we covered these aspects in two other posts: Adenosine, the Good & 4 Ways to Increase It and Adenosine, the Bad & 4 Ways to Lower it.
This post focuses only on the use of adenosine as a drug.
What Is Adenosine (Adenocard)?
Adenocard is one of the brand names adenosine is available under. The drug is produced under various other trade names, including:
- Adenocor
- Adenic
- Adenoco
- Adeno-Jec
- Adenoscan
- Adenosin
- Adrekar
- Krenosin
Adenosine is approved by the FDA and widely used for treating surgical pain, nerve pain, lung hypertension, and certain types of irregular heartbeat (arrhythmias) [1, 2, 3, 4].
It is also used to maintain low blood pressure during medical procedures and to help visualize arteries for diagnosis and aneurysm repair [5, 6, 7].
Drug Class
Adenosine is classified as a miscellaneous antiarrhythmic drug. Unlike adenosine, other drugs for treating arrhythmias are categorized under classes I to IV of antiarrhythmic agents (Vaughan-Williams classification scheme) [8].
How It Works
Adenosine acts as an activator (agonist) on (purinergic) adenosine receptors throughout the body. Four adenosine receptors have been identified (A1, A2a, A2B, and A3), but as a drug, it mainly activates receptors in the so-called cardiac atrioventricular (AV) nodal tissue and those within the blood vessels to achieve its therapeutic effects [8].
Uses of Adenosine (Adenocard)
Approved Uses
Prescription adenosine is mainly approved for the treatment of irregular heartbeat and for its use as a diagnostic tool. Follow your doctor’s instructions carefully. Take adenosine as recommended and do not change its dose and frequency or stop taking it without your doctor’s approval. Talk to your doctor if your condition doesn’t improve or if it worsens.
1) Irregular Heartbeat (Arrhythmia)
An irregular heartbeat can be triggered by many factors, including mental stress or panic attacks, anxiety, medication, alcohol, stimulant psychoactive substances, and genetic disorders. Most often, it is associated with heart disease [9, 10, 11, 12].
SVT
Adenosine is used to treat certain types of irregular heartbeat called paroxysmal supraventricular tachycardia or SVT [13].
Several observational studies showed that adenosine, as a drug, works by slowing down the electrical signals that pass through the area of the heart (atrioventricular or AV node) that controls heart rate and therefore, may be used safely and effectively for SVTs [14, 15, 16, 17].
2) Visualizing Aneurysms & Surgery
An aneurysm is a weakening or thinning of a blood vessel wall in the brain that could lead to rupture, resulting in life-threatening leakage or bleeding.
During aneurysm surgery, adenosine temporarily stops blood from flowing to the heart. In this particular situation, adenosine causes a short period of controlled low blood pressure that allows the surgeon to visualize and repair the aneurysm [18, 7, 19, 20, 21].
Adenosine is used to maintain low blood pressure (induced hypotension) in patients during surgeries to reduce blood loss and prevent the need to replace blood [22, 23].
3) Adenosine Stress Test
Stress testing is a method used to diagnose certain types of heart disease, including coronary artery disease.
During the test, adenosine is often used (as an alternative to exercise) to increase blood flow before performing the diagnostic heart ultrasound (echocardiogram) or heart magnetic resonance imaging (MRI) [24, 25].
Off-Label Uses
Adenosine is not approved by the FDA for the following conditions, but some doctors may prescribe them in some cases. Carefully follow their recommendations and seek medical attention if your condition doesn’t improve or you experience severe or mild but persistent adverse effects.
1) Pain Relief
Nerve pain is caused by injury or disease that is often characterized by severe shooting pain or burning sensations.
An observational study showed lower levels of adenosine circulating in the blood of patients experiencing nerve pain [2].
Clinical trials and observational studies showed that adenosine (administered intravenously) can have pain-relieving effects that last for days or even months. It relieved pain in [26, 27, 28]:
- People undergoing surgery
- Difficult-to-treat pain in the peripheral or central nervous system (brain and spinal cord)
- Increased sensitivity to pain (hyperalgesia and allodynia) due to injury
Adenosine is not used to treat chronic pain, mainly because of the potential side effects [1].
2) High Blood Pressure in the Lungs
High blood pressure in the lungs (pulmonary hypertension) is a serious condition that can be caused by heart disease or a blood clot or can occur following a heart operation. Adenosine can reduce the increased blood pressure in blood vessels of the lungs [29, 30, 31].
Side Effects & Precautions
This list does not cover all possible side effects. Contact your doctor or pharmacist if you notice any other side effects.
Call your doctor for medical advice about side effects. In the US, you may report side effects to the FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada, you may report side effects to Health Canada at 1-866-234-2345.
Adenosine is typically only used in medical environments, although rare, life-threatening situations can arise.
In one case report, a high dose of adenosine led to a severe arrhythmia that required an additional medical procedure to restore the normal heart rhythm [19].
Side effects normally last less than a minute after administering adenosine and are mainly the result of increased blood flow caused by the widening of the blood vessels (vasodilation).
The main side effects can include [25, 32, 33+, 34+, 35, 1]
- Facial flushing or redness
- A rash on the chest
- Lightheadedness
- Sweating
- Nausea
- Metallic taste
- Chest discomfort
- Shortness of breath
- Throat/neck/jaw discomfort
- Abdominal pain
- Low blood pressure (hypotension)
- Nervousness
- Irregular heartbeat (arrhythmia)
More serious side effects include [19, 36]
- Life-threatening arrhythmia (irregular heartbeat)
- Heart attack
Contraindications
Adenosine should also not be given to patients experiencing tightness of the chest (bronchospasm or asthma), Wolff-Parkinson-White (WPW) syndrome (a rare disease that causes irregular heart rhythms), or a low heart rate (bradycardia), since it can worsen symptoms [37, 38].
Food and drinks that contain caffeine, such as coffee, tea, cola, and chocolate, can increase the risk of side effects from adenosine.
Drug Interactions
The following drugs may interact with adenosine:
- Dipyridamole (Persantine) prevents the breakdown of adenosine so the two should not be taken together.
- Carbamazepine (Tegretol) and adenosine taken together could result in a dangerously low heart rate.
- Medications for Gout may be less effective since Gout is an autoimmune disease that leads to a buildup of uric acid in joints and uric acid is produced by the breakdown of adenosine.
Dosage
To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. Talk to your healthcare provider to find out how adenosine might interact with something else you are taking.
For irregular heartbeat (tachycardia), doses of 0.1-0.3 mg/kg intravenous adenosine are most effective [39, 40, 41].
It can be safe after heart transplantation, which commonly causes this type of irregular heartbeat, but at much lower doses (0.025 mg/kg) [42].
Finally, 50 μg/kg/min was administered over 60 min in clinical trials for pain relief [43].
Takeaway
Adenosine (Adenocard) is approved by the FDA and widely used for treating arrhythmias (SVT), surgical pain, nerve pain, and lung hypertension. It is also used to maintain low blood pressure during surgery and to help visualize arteries for aneurysm repair. Adenosine is classified as a miscellaneous antiarrhythmic drug, unlike other antiarrhythmic agents. It achieves its therapeutic effects by acting as an agonist on adenosine receptors in the AV nodal tissue and those in blood vessels.
