Related Subjects:
|Wolff-Parkinson White syndrome (WPW) AVRT
|Lown Ganong Levine Syndrome AVRT
|Supraventricular Tachycardia (SVT)
|Atrioventricular Nodal Reentrant Tachycardia AVNRT
|Atrial Flutter
|Atrial Fibrillation
|Sinus Tachycardia
|Sinus Arrhythmia
|Multifocal Atrial Tachycardia
|Resuscitation - Adult Tachycardia Algorithm
⚡ Patients often feel an intense, unpleasant sensation for 20–30 seconds after adenosine - this is always transient.
✅ Reassure them it will quickly pass.
🚫 Do not use in asthmatics (risk of severe bronchospasm).
📖 About
- Purine nucleotide used to treat supraventricular tachycardias (SVTs).
- Adenosine receptor agonist (mainly A1 receptors in the heart).
- Always check the BNF link here.
⚙️ Mode of Action
- Activates A1 purinergic receptors at the SAN and AVN.
- Inhibits adenylate cyclase → ↓cAMP → increased outward K+ flux.
- Causes hyperpolarisation of nodal tissue → slows AV nodal conduction.
🫀 Actions
- Produces transient AV block, bradycardia, or even brief asystole.
- Does not cardiovert AF or flutter, but may transiently slow AV conduction and unmask flutter waves.
- Also acts as a vasodilator → flushing, hypotension.
- Very short half-life (<10 seconds) → must reach the AV node before metabolism.
💉 Dose & Administration – Adenosine (verify with BNF/datasheet)
| Indication / Context |
Details |
⚡ Sensitised patients
(on dipyridamole, carbamazepine, post-transplant, or via central line) |
Adenosine
• Dose: 1–3 mg stat
• Route: Rapid IV bolus into large vein
• Flush: Immediately with 20 mL 0.9% NaCl
|
| ➡️ Standard first dose |
Adenosine
• Dose: 6 mg stat
• Route: Rapid IV bolus + 20 mL NS flush
• Note: If ineffective, escalate
|
| 🔁 If 6 mg ineffective |
Adenosine
• Dose: 12 mg stat (may repeat once)
• Route: Rapid IV bolus + 20 mL NS flush
|
| 💡 Administration Notes |
• Give via large peripheral or central vein
• Follow immediately with 20 mL NS flush
• Warn patient of transient unpleasant effects (flushing, chest pressure, breathlessness, sense of doom)
|
🩺 Indications
- Termination of paroxysmal SVTs (AVNRT, AVRT).
- Diagnostic aid: can unmask atrial flutter/fibrillation waves.
- Used in myocardial perfusion imaging (diagnostic pharmacology).
🚫 Contraindications
- Asthma or severe COPD (risk of bronchospasm) → consider verapamil instead.
- Long QT syndrome, sick sinus syndrome, 2nd/3rd-degree AV block (unless paced).
- Heart transplant patients: extremely sensitive (use lower dose).
⚠️ Side Effects
- Transient: chest discomfort, flushing, dyspnoea, nausea, sense of impending doom.
- Bradyarrhythmia, sinus pause, complete heart block (short-lived).
- Bronchospasm in susceptible patients.
🔄 Interactions
- Dipyridamole: potentiates effect → use reduced starting dose (as low as 1 mg).
- Theophylline/aminophylline: antagonise adenosine → reduced effect.
- Carbamazepine: enhances AV block → use lower doses.
📚 References
