Adenosine

Indications

Adenosine is used for: Paroxysmal supraventricular tachycardia, Supraventricular tachycardia

Adult Dose

Intravenous Differential diagnosis of supraventricular tachycardias Adult: Initially, 3 mg by rapid IV inj into a central or large peripheral vein over 2 sec with cardiac monitoring; 6 mg may be given after 1-2 minutes if necessary, then 12 mg after a further 1-2 minutes. Avoid increments if high level AV block occurs at any particular dose. Paroxysmal supraventricular tachycardia Adult: Initially, 3 mg by rapid IV inj into a central or large peripheral vein over 2 sec with cardiac monitoring; 6 mg may be given after 1-2 minutes if necessary, then 12 mg after a further 1-2 minutes. Avoid increments if high level AV block occurs at any particular dose. Myocardial imaging Adult: 140 mcg/kg/minute by infusion for 6 minutes. Inject radionuclide 3 minute after infusion.

Child Dose

Intravenous Differential diagnosis of supraventricular tachycardias Child: Initially, 50-100 mcg/kg; if necessary, may increase dose by 50-100 mcg/kg increments at 1-2 minute intervals or until arrhythmia is controlled. Max dose: 300 mcg/kg. Paroxysmal supraventricular tachycardia Child: Initially, 50-100 mcg/kg; if necessary, may increase dose by 50-100 mcg/kg increments at 1-2 minute intervals or until arrhythmia is controlled. Max dose: 300 mcg/kg. Myocardial imaging Adult: 140 mcg/kg/minute by infusion for 6 minutes. Inject radionuclide 3 minute after infusion.

Renal Dose

Administration

IV Administration Adenocard: given as a rapid injection (1-3 sec) by peripheral IV route directly into vein or into IV line close (proximal) to patient & is followed by rapid NS flush after each inj (20 mL for adults, 5 mL or more for peds) Place pt in mild reverse Trendelenburg position before giving drug.

Contra Indications

2nd or 3rd degree AV block and sick sinus syndrome (unless pacemaker fitted), asthma, hypersensitivity.

Precautions

Pregnancy; heart transplant patients; patients on dipyridamole (lower initial dose of adenosine 0.5-1 mg); atrial fibrillation or flutter with accessory pathway (conduction along anomalous pathway may increase). Lactation: Potential for serious adverse reactions in nursing infants; decision to interrupt nursing after administration of adenosine or not should take into account importance of drug to mother.

Pregnancy-Lactation

Pregnancy Category: C Lactation: Potential for serious adverse reactions in nursing infants; decision to interrupt nursing after administration of adenosine or not should take into account importance of drug to mother

Interactions

Adenosine effects antagonised by methylxanthines like caffeine, theophylline, etc. Concomitant carbamazepine may increase the risk of heart block. Potentially Fatal: Adenosine effects are potentiated by dipyridamole.

Side Effects

Side effects of Adenosine : >10% Flushing (18%), Dyspnea (12%) 1-10% Chest pain (7%), HA (2%), Lightheadedness (2%), Dizziness (1%), Tingling in arms (1%), Numbness (1%), Nausea (3%) <1% Hypotension, Palpitations, Apprehension, Head pressure, Chest pain, Hyperventilation, Blurred vision, Burning sensation, Heaviness in arms, neck & back pain, Metallic taste, Tightness in throat, Pressure in groin, Sweating

Mode of Action

Adenosine acts rapidly to slow down conduction through the AV node via the A1 receptors. It also mediates peripheral and coronary vasodilatation by stimulating the A2 receptors. Extremely short plasma half-life (<10 sec) permits dosage titration during IV use every 1-2 min and causes no concern of cumulative effect through repeated dosing.