Antiarrhythmic (Purinergic) Pregnancy: There are no or limited data from use in pregnant women and animal studies are insufficient with respect to reproductive toxicity; adenosine is not recommended during pregnancy unless the physician considers the benefits to outweigh the potential risks. It is unknown whether adenosine metabolites are excreted in human milk — should not be used during breast-feeding.

Adenosine

Brand names: Adenocor

Adenosine is an endogenous purine nucleoside given as a rapid intravenous bolus to terminate paroxysmal supraventricular tachycardia and to aid diagnosis of broad- or narrow-complex tachycardias.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Ascending schedule: initial dose 3 mg; if the first dose does not eliminate the supraventricular tachycardia within 1 to 2 minutes, give 6 mg; if the second dose does not eliminate it within 1 to 2 minutes, give 12 mg

Route: Rapid intravenous bolus injection (over 2 seconds), given directly into a vein or into an IV line as proximally as possible and followed by a rapid saline flush; a large bore cannula should be used if administered through a peripheral vein

Frequency: Single ascending boluses, each given if the tachycardia persists 1 to 2 minutes after the previous dose

Max: 12 mg — additional or higher doses are not recommended

Source: UK SPC (eMC) for Adenosine 3 mg/ml solution for injection, §4.2 (https://www.medicines.org.uk/emc/product/11530/smpc). Intended for hospital use only, with monitoring and cardiorespiratory resuscitation equipment available for immediate use; should only be used where facilities exist for cardiac monitoring, and continuous ECG monitoring is necessary during administration as life-threatening arrhythmia might occur. Patients who develop high-level AV block at a particular dose should NOT be given further dosage increments. ELDERLY: see dosage recommendations for adults. DIAGNOSTIC USE: the same ascending dosage schedule should be employed until sufficient diagnostic information has been obtained; method of administration is rapid intravenous injection only. Each vial is for single use; examine the solution visually for particulate matter and discoloration before administration and use only a clear, colourless solution. The occurrence of angina, severe bradycardia, severe hypotension, respiratory failure (potentially fatal) or asystole/cardiac arrest (potentially fatal) should lead to immediate discontinuation. Adenosine may trigger convulsions in susceptible patients. Persistent side effects have been terminated with methylxanthines such as IV aminophylline or theophylline (50-125 mg by slow intravenous injection) (§4.8). §4.5 was not retrieved in this bundle — the interaction listed below is from §4.4; verify the full §4.5. NOTE ON SOURCES: the openFDA entry in this bundle is an unrelated topical sunscreen product ('PETITCOCHON TONE UP BODY SUN') and was NOT used for any content here.

Paediatric dose

Dose: 0.1 mg/kg

Route: Rapid intravenous bolus injection into a vein or into an IV line (as proximally as possible), followed by a rapid saline flush

Frequency: First bolus 0.1 mg/kg, then increments of 0.1 mg/kg body weight as needed to achieve termination of the supraventricular tachycardia

Max: First bolus maximum 6 mg; increments up to a maximum dose of 12 mg

SPC §4.2: dosing recommended for the treatment of paroxysmal supraventricular tachycardia in the paediatric population. Cardio-respiratory resuscitation equipment must be available for immediate use, with continuous monitoring and ECG recording during administration. Verify against a children's formulary and local paediatric resuscitation guidance before use.

Dose adjustments

Renal

Since neither the kidney nor the liver is involved in the degradation of exogenous adenosine, efficacy should be unaffected by hepatic or renal insufficiency (§4.4). No dose adjustment is stated.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

Patient weight (kg)

Verify in a children's formulary

Contraindications

Known hypersensitivity to adenosine or to any of the excipients
Sick sinus syndrome, second or third degree atrioventricular (AV) block (except in patients with a functioning artificial pacemaker)
Chronic obstructive lung disease with evidence of bronchospasm (e.g. asthma bronchiale)
Long QT syndrome
Severe hypotension
Decompensated states of heart failure

Side effects

Very common cardiac effects: bradycardia, sinus pause/skipped beats, atrial extrasystoles, atrioventricular block, ventricular excitability disorders (ventricular extrasystoles, non-sustained VT)
Very common: flushing; dyspnoea or the urge to take a deep breath; chest pressure/pain, feeling of thoracic constriction
Common: headache, dizziness/light-headedness, apprehension, nausea, burning sensation
Very rare / not known: severe bradycardia not corrected by atropine (possibly requiring temporary pacing), atrial fibrillation, ventricular fibrillation and torsade de pointes, hypotension sometimes severe, asystole/cardiac arrest sometimes fatal, coronary arteriospasm which may lead to myocardial infarction
Respiratory: very rare bronchospasm; not known respiratory failure, apnoea/respiratory arrest — cases with fatal outcome have been reported
Not known: loss of consciousness/syncope, convulsions especially in predisposed patients, anaphylactic reaction (including angioedema, urticaria and rash). Effects are generally mild and of short duration (usually less than 1 minute), but severe reactions can occur

Interactions

Dipyridamole (a known inhibitor of adenosine uptake) may potentiate the action of adenosine — adenosine should not be given to patients receiving dipyridamole; if its use is essential, dipyridamole should be stopped 24 hours beforehand or the adenosine dose greatly reduced (§4.4)
Methylxanthines (IV aminophylline or theophylline 50-125 mg by slow intravenous injection) have been used to terminate persistent side effects (§4.8)
§4.5 was not retrieved in this bundle — verify the full interaction section

Clinical monograph

How it works

Acting on A1 receptors it transiently slows conduction through the atrioventricular node, interrupting re-entry circuits that depend on the AV node and restoring sinus rhythm.

Prescribing in practice

It can cause transient asystole, profound bradycardia, and bronchospasm, so it must be given with continuous ECG and resuscitation facilities and used cautiously or avoided in asthma.
Because its half-life is extremely short it must be given as a rapid bolus into a large proximal vein followed by an immediate saline flush.
Effect is potentiated by dipyridamole and antagonised by caffeine and theophylline, and it should be avoided in second- or third-degree heart block without a pacemaker.

Monitoring

Record continuous ECG during administration to capture the rhythm response and to detect transient pauses, AV block, or new arrhythmia.

Counselling the patient

Warn the patient they may briefly feel flushing, chest tightness, or a sense of impending doom that passes within seconds.
Reassure that these effects are short-lived because the drug is broken down very quickly.
Explain the heart rhythm is being recorded throughout to guide treatment.

Evidence & guidelines

Adenosine is the first-line agent for terminating AV-nodal-dependent supraventricular tachycardia in UK and Resuscitation Council tachycardia algorithms.

Reference: Resuscitation Council UK ACLS Guidelines 2021; ESC SVT Guidelines 2019; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

SVT Termination Score and Adenosine Dosing · Arrhythmia

Pathways