Adenosine

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  • Class of drug: Antiarrhythmic.
  • Mechanism of action: Vagolytic effect: Slows conduction through AV node; prevents reentry through AV node. Restores normal sinus rhythm in patients with paroxysmal supraventricular tachycardia including Wolff–Parkinson–White syndrome.
  • Indications/dosage/route: IV only.
    Paroxysmal supraventricular tachycardia
    Ð Adults: bolus of 6 mg. If no effect after 1–2 min, 12-mg bolus. May repeat 12-mg dose × 2.
  • Adjustment of dosage•
    Kidney disease: None.
    Liver disease: None.
    Elderly: None.
  • Contraindications:
    Second- or third-degree AV block (without pacemaker), sick sinus syndrome, symptomatic bradycardia.
  • Warnings/precautions
    Use with caution in patients with the following condition:
    Stroke, asthma, unstable angina (higher risk of arrythmias, MI).
    Cardiac arrest (including fatalities), ventricular tachycardia, and MI have been reported coincident with use.
    May produce transient first-, second-, third-degree AV block.
    Asystole has been reported in atrial flutter when given with carbamazepine.
    Use cautiously in patients receiving digoxin and/or verapamil.
    May cause ventricular fibrillation.
    Resuscitative equipment should be readily available when adenosine is administered.
    May produce hypotension or hypertension as side effects.
    May cause bronchoconstriction in patients with asthma or COPD.
  • Advice to patient

It is necessary to inject adenosine rapidly by peripheral IV route followed by saline bolus because of its short half-life. Solution should be checked for presence of crystals; if present, warm solution. Do not inject if crystals are present.

  • Adverse reactions
    Common: facial flushing (18%), nausea, hyperventilation, thoracic constriction, palpitations.
    Serious: hypotension, dyspnea (12%), heart block, ventricular fibrillation, asystole, hypertension.

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