ADENOSINE (a-den'o-sin)
Adenocard, Adenoscan Classifications: antiarrhythmic agent; Therapeutic: antiarrhythmic Pregnancy Category: C
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Availability
3 mg/mL
Action
Slows conduction through the atrioventricular (AV) and sinoatrial (SA) nodes. Can interrupt the reentry pathways through
the AV node.
Therapeutic Effect
Restores normal sinus rhythm in patients with paroxysmal supraventricular tachycardia.
Uses
Conversion to sinus rhythm of paroxysmal supraventricular tachycardia (PSVT) including PSVT associated with accessory bypass
tracts (Wolff-Parkinson-White syndrome). "Chemical" thallium stress test.
Unlabeled Uses
Afterload-reducing agent in low-output states; to prevent graft occlusion following aortocoronary bypass surgery; to produce
controlled hypotension during cerebral aneurysm surgery.
Contraindications
AV block, preexisting second- and third-degree heart block or sick sinus rhythm without pacemaker, since a heart block may
result; pregnancy (category C). Ineffective for atrial flutter, atrial fibrillation, and ventricular tachycardia.
Cautious Use
Asthmatics, unstable angina, stenotic valvular disease, hypovolemia; hepatic and renal failure.
Route & Dosage
Supraventricular Tachycardia Adult/Adolescent (≥50 kg): IV 6 mg bolus initially; after 12 min may give two additional 12 mg bolus doses for a total of 3 doses. Do not exceed
12 mg in any one dose. Neonate/Infant/Child: IV 0.051 mg/kg bolus; additional doses may be increased by 0.051 mg/kg q2 min (max: 12 mg/dose)
Stress Thallium Test Adult: IV 140 mcg/kg/min x 6 min (max: 0.84 mg/kg total dose)
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Administration
Intravenous
- Make sure solution is clear at time of use.
- Discard unused portion (contains no preservatives).
PREPARE: Direct: No dilution is required.
ADMINISTER: Direct: Administer directly into vein as a rapid bolus over 12 s. If given by IV line, administer as proximally as possible,
and follow with a rapid saline flush.
- Note: If high-level block develops after one dose, do not repeat dose.
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- Store at room temperature 15°30° C (59°86° F). Do not refrigerate, as crystallization may
occur. If crystals do form, dissolve by warming to room temperature.
Adverse Effects (≥1%)
CNS: Headache, lightheadedness, dizziness, tingling in arms (from
IV infusion), apprehension, blurred vision, burning sensation
(from
IV infusion).
CV: Transient facial flushing, sweating, palpitations, chest pain, atrial fibrillation or flutter.
Respiratory: Shortness of breath, transient
dyspnea, chest pressure.
GI: Nausea, metallic taste, tightness in throat.
Other: Irritability in children.
Interactions
Drug: Dipyridamole can potentiate the effects of adenosine;
theophylline will block the electrophysiologic effects of adenosine;
carbamazepine may increase risk of heart block.
Pharmacokinetics
Absorption: Rapid uptake by
erythrocytes and vascular endothelial cells after
IV administration.
Onset: 2030 s.
Metabolism: Rapid uptake into cells; degraded by deamination to inosine, hypoxanthine, and adenosine monophosphate.
Elimination: Route unknown.
Half-Life: 10 s.
Nursing Implications
Assessment & Drug Effects
- Monitor for S&S of bronchospasm in asthma patients. Notify physician immediately.
- Use a hemodynamic monitoring system during administration; monitor BP and heart rate and rhythm continuously for several
minutes after administration.
- Note: Adverse effects are generally self-limiting due to short half-life (10 s).
- Note: At the time of conversion to normal sinus rhythm, PVCs, PACs, sinus bradycardia, and sinus tachycardia, as well as various
degrees of AV block, are seen on the ECG. These usually last only a few seconds and resolve without intervention.
Patient & Family Education
- Note: Flushing may occur along with a feeling of warmth as drug is injected.