Adenosine

For narrow-complex regular SVT after vagal manoeuvres: 6 mg, then 12 mg, then 18 mg rapid IV push with a fast flush.

Antiarrhythmic (AV nodal blocker)Reviewed October 2026

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Dose

Step	Dose
1	6 mg rapid IV push into a large proximal vein, with a 20 mL saline flush
2	12 mg if no response after 1–2 minutes
3	18 mg if still no response (Resus Council UK)
Children	100 micrograms/kg, then 200 micrograms/kg, then 300 micrograms/kg (max 12 mg per dose)

Cautions

Warn the patient: a brief feeling of chest tightness or impending doom.
Run an ECG strip during administration.
Avoid in severe asthma, pre-excited AF, second- or third-degree heart block.
Reduce the dose with dipyridamole or after heart transplant.

Frequently asked questions

Why is adenosine given so quickly?

It has a half-life of seconds, so it must reach the heart as a rapid bolus followed by a flush.

Used in these guides

Sources

Drugs.com: Adenosine dosage

Doses on this page are typical doses from the sources above. Always confirm with a current drug reference, the product leaflet and your hospital protocol, especially in children, pregnancy and kidney or liver disease.

For FCPS Part 1

Revising for FCPS Part 1? Adenosine is covered in our textbook chapter Antiarrhythmic and antianginal drugs, with practice MCQs.