What the label lists and what reports show
Adenosine side effects
Adenosine's FDA label: “Most common adverse reactions (incidence ≥ 10%) are: flushing; chest discomfort; shortness of breath; headache; throat, neck or jaw discomfort; gastrointestinal discomfort; …” FAERS holds 1,600 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is supraventricular tachycardia (98 reports).
- Generic listed
Check it at the source: the adenosine FDA label on DailyMed (effective April 14, 2025, Meitheal Pharmaceuticals Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥ 10%) are: flushing; chest discomfort; shortness of breath; headache; throat, neck or jaw discomfort; gastrointestinal discomfort; and dizziness ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Meitheal Pharmaceuticals, Inc.
A table the label prints in its adverse reactions section without a title; its column headings name the groups compared
| Adverse Reactions | Adenosine N=1,421 |
|---|---|
| Flushing | 44% |
| Chest discomfort | 40% |
| Dyspnea | 28% |
| Headache | 18% |
| Throat, neck or jaw discomfort | 15% |
| Gastrointestinal discomfort | 13% |
| Lightheadedness/dizziness | 12% |
| Upper extremity discomfort | 4% |
| ST segment depression | 3% |
| First-degree AV block | 3% |
| Second-degree AV block | 3% |
| Paresthesia | 2% |
| Hypotension | 2% |
| Nervousness | 2% |
| Arrhythmias | 1% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed in more detail in other sections of the prescribing information: Fatal Cardiac Arrest, Ventricular Arrhythmias, and Myocardial Infarction [see Warnings and Precautions ( 5.1 )] Sinoatrial and Atrioventricular Nodal Block [see Warnings and Precautions ( 5.2 )] Bronchoconstriction [see Warnings and Precautions ( 5.3 )] Hypotension [see Warnings and Precautions ( 5.4 )] Cerebrovascular Accident [see Warnings and Precautions ( 5.5 )] Seizures [see Warnings and Precautions ( 5.6 )] Hypersensitivity [see Warnings and Precautions ( 5.7 )] Atrial fibrillation [see Warnings and Precautions ( 5.8 )] Hypertension [see Warnings and Precautions ( 5.9 )] Most common adverse reactions (incidence ≥ 10%) are: flushing; chest discomfort; shortness of breath; headache; throat, neck or jaw discomfort; gastrointestinal discomfort; and dizziness ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Meitheal Pharmaceuticals, Inc. at 1-844-824-8426 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Source: FDA drug label, Meitheal Pharmaceuticals Inc., effective April 14, 2025 (SPL set b6851256-6cef-4f23-8129-19bb64380cd5), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,600 reports list adenosine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 142 are coded as a death and 758 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 11 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Adenosine: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions