Naturally occurring nucleoside that stimulates specific adenosine receptors. This results in activation of acetylcholine sensitive potassium channels (efflux of potassium) and blockade of calcium influx in the SA node, atrium and AV node. The cells become hyperpolarized and this blunts SA node discharge
Onset – rapid
Duration - very brief
Half-Life - 6 to 10 seconds
Duration - 1 to 2 minutes
Conversion of supraventricular tachycardia (SVT) / paroxysmal supraventricular tachycardia (PSVT).
2nd or 3rd degree AV block, or sick sinus syndrome (without pacemaker)
May worsen bronchospasm in asthmatics and some patients with COPD.
Drug to drug interactions
Higher than normal doses of Adenosine may be required for patients on xanthines (eg. theophylline).
Lower than normal doses (i.e. 3 mg or less) should be used for patients on dipyridamole (Persantine) as this drug potentiates Adenosine.
The effects of Adenosine are prolonged in patients taking Carbamazepine (anti-convulsant) and in heart transplant recipients (denervated hearts).
Dizziness/light headedness/syncope, facial flushing, dyspnea or shortness of breath, gastroninestinal distress (nausea/vomiting), chest pain or discomfort
Usually resolves in 1-2 mins
Explain to the patient they will likely experience some of the above symptoms and that the symptoms are temporary
First dose: 6 mg IV direct, given rapidly and immediately followed with 20 mL to 30 mL IV NS or RL flush
Run ECG strip as drug is being given
If no conversion to sinus rhythm or slowing of rhythm to diagnose underlying rhythm (e.g. atrial flutter or atrial fibrillation) in 1-2 minutes, can give a second dose: 12 mg IV direct, rapid administration followed by 20-30 mL IV NS or RL flush
Note: Adenosine must be given very quickly and in the IV site closest to the central circulation (e.g. antecubital, external jugular, central line). It should always be immediately followed by a 20-30 cc flush of NS or RL to make sure that all of the drug is cleared from the IV tubing and delivered to the intended site.
0.1 mg/kg IV direct (maximum 12 mg as a single dose), given rapidly followed by 5-10 mL (depends on weight of child) IV NS or RL
If no conversion to sinus rhythm or slowing of rhythm to diagnose underlying rhythm (e.g. atrial flutter or atrial fibrillation) in 1-2 minutes, can double the dose and repeat (maximum 12 mg as a single dose)
Has a > 90% successful conversion of PSVT rate when the full dose is given (Crankin et al, 1989; Garrat et al, 1989; DiMarco et al, 1990).
Has an extremely short half life of 10 seconds or less – consequently, as many as 40% of patients may revert back into PSVT.
Once the drug is given, the patient may experience a period of asystole of 3-15 seconds. A variety of other rhythms may also appear on the ECG ( e.g. second or third-degree heart block). Because of the drug's short half life, these effects are generally self-limiting
Sometimes rapid Atrial Fibrillation is difficult to distinguish from a regular SVT. If that occurs turn the volume up on the cardiac monitor. This will provide an auditory clue that the rhythm is irregularly irregular. Map out the R-R interval to see if the rhythm is regular (SVT) or irregular (A. Fib.). Use the patient’s history and medications as a guide – i.e. the elderly patient on digoxin and coumadin is more likely to be in an atrial fib. The younger patient is more likely to be in an SVT.
Transport of the patient should not be delayed as other treatments/drugs may be required in hospital should SVT/PSVT recur