Adenosine
AdenocardPubChem CID 60961 · 3D model
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Briefly opens potassium channels and closes calcium channels in the heart's AV node, causing a split-second 'reset' that breaks the electrical short-circuit behind certain racing heartbeats — an effect so short-lived it's gone from the bloodstream in under 10 seconds.
How it works
Adenosine is a chemical the body already makes, and as a drug it's given as a fast IV push to briefly 'reset' the heart's electrical relay station, the AV node, when it's stuck in a rapid, looping rhythm called SVT. It works by very briefly opening potassium channels and closing calcium channels in the AV node's cells, making them harder to excite for a second or two and breaking the short-circuit loop causing the fast heartbeat. That effect is over almost as fast as it starts — the drug clears from the blood in under 10 seconds — which is the opposite of amiodarone, also on this site, a drug that works slowly and broadly across the whole heart over hours or weeks.
What it’s used for
Adenosine is the go-to emergency drug for quickly stopping a specific type of racing heartbeat called paroxysmal supraventricular tachycardia (PSVT, including the kind linked to Wolff-Parkinson-White syndrome). It's given as a fast IV push, usually after doctors try a simple maneuver like bearing down. It won't fix other irregular rhythms like atrial fibrillation, though it can briefly slow the heart rate in those conditions too.
- Mechanism
- Adenosine A1-receptor agonist (AV-nodal blocker)
- Drug class
- Small molecule
- Therapeutic area
- Cardiovascular