Adenosine
Mechanism :
Adenosine is an endogenous nucleoside occurring in all cells of the body. It
slows conduction time through the A-V node, and can interrupt the re-entry pathways through the A-V node, therefore can restore normal sinus rhythm in patients with paroxysmal supraventricular tachycardia (PSVT), including PSVT associated with Wolff-Parkinson-White Syndrome.
Indication :
- PSVT to convert to sinus rhythm, including those associated with accessory bypass tracts WPW syndrome.
- Diagnostic to elucidate mechanism of tachycardia.
Contraindications :
Second- or third-degree A-V block.
Sinus node disease, such as sick sinus syndrome or symptomatic bradycardia.
Known hypersensitivity to adenosine.
Dosing :
Children with a Body Weight <50 kg
Initial dose: 0.05 to 0.1 mg/kg as a rapid IV bolus given either centrally or peripherally.
Repeat administration: If conversion of PSVT does not occur within 1-2 minutes, additional bolus injections of adenosine can be administered at incrementally higher doses, increasing the amount given by 0.05 to 0.1 mg/kg. Follow each bolus with a saline flush. This process should continue until sinus rhythm is established. (Cumulative dose of 12 mg should not be exceeded).
Children with a Body Weight >50 kg
Initial dose: 6 mg given as a rapid intravenous bolus (administered over a 1-2 second period).
Repeat administration: If the first dose does not result in elimination of the supraventricular tachycardia within 1-2 minutes, 12 mg should be given as a rapid intravenous bolus. This 12 mg dose may be repeated a second time if required.
Max dose: 12 mg/dose or cumulative dose of 30 mg.
For diagnostic test for tachycardia:
0.1 mg/kg IV followed by 0.2 mg/kg IV given with a rapid IV push over 1-3 seconds.
Maximum dose: 6 mg initial dose.
Adverse Effect :
Transient chest pain, bradycardia, dyspnoea, diaphoresis, facial flushing, headache, nervousness, numbness, paraesthesia, bronchospasm, chest pain, hemolytic anemia, choking, tingling in arms and light headedness.
Interaction :
Dipyridamole: Enhanced effect, reduce dose of adenosine.
Theophylline/xanthines: Antagonise action.
Caffeine: May diminish the therapeutic effect of Adenosine.
Carbamazepine: May enhance the adverse/toxic effect of Adenosine. Specifically, the risk of higher degree heart block may be increased. Management: Consider using a lower initial dose of adenosine in patients who are receiving carbamazepine.
Digoxin: May enhance the adverse/toxic effect of Adenosine.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in normal renal function |
| HD | Not dialysed. Dose as in normal renal function |
| HDF/High flux | Unknown dialysability. Dose as in normal renal function |
| CAV/VVHD | Not dialysed. Dose as in normal renal function |
Hepatic Dose :
No dosage adjustments are recommended.