ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Antiarrhythmic Pregnancy: C — acceptable if needed for SVT

Adenosine

Brand names: Adenocor

Adult dose

Dose: 6mg, then 12mg, then 12mg
Route: Rapid IV bolus (antecubital or central)
Frequency: 30–60 sec between doses
Max: 30mg total
Give 6mg as a RAPID bolus over 1–2 sec, immediately followed by 20ml saline flush. If no response within 1–2 min, give 12mg. Repeat 12mg once more. Reduce to 3mg in patients on dipyridamole or with heart transplant.

Paediatric dose

Dose: 0.1 mg/kg
Route: Rapid IV
Frequency: 30–60 sec between doses
Max: 6mg
Concentration: 3 mg/ml
Paediatric weight-based calculator

Clinical pearls

  • MUST be given as a rapid bolus (1–2 sec) with immediate 20ml saline flush — half-life <10 sec, slow injection is ineffective.
  • Prefer antecubital fossa over hand veins for faster delivery to AV node.
  • Terminates SVT by transiently blocking the AV node. Does NOT terminate AF/flutter — but unmasks flutter waves (diagnostic).
  • Warn patient about transient but distressing symptoms before administration.
  • Paed: initial 0.1mg/kg (max 6mg), then 0.2mg/kg (max 12mg), then 0.3mg/kg (max 12mg).

Contraindications

  • Second or third degree AV block (without pacemaker)
  • Sick sinus syndrome (without pacemaker)
  • Long QT syndrome
  • Severe asthma or significant COPD
  • Decompensated heart failure
  • Dipyridamole use (markedly potentiates adenosine)

Side effects

  • Flushing, chest tightness, dyspnoea — very common, brief (10–20 sec)
  • Transient sinus pause or AV block
  • Bronchospasm — avoid in asthma
  • Rarely: hypotension, VF (very rare)

Interactions

  • Dipyridamole: markedly potentiates effect — reduce dose by 75% or avoid
  • Theophylline / caffeine: antagonises adenosine — larger doses may be required
  • Carbamazepine: increased risk of AV block
  • Heart transplant: enhanced sensitivity — use 1–3mg initial dose

Monitoring

  • Continuous ECG mandatory. Resuscitation equipment at bedside.

Reference: BNFc; NICE BNF 84; ESC SVT Guidelines 2019. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Pathways