From the Guidelines
For supraventricular tachycardia (SVT), adenosine is administered as a rapid IV bolus with the initial dose being 6 mg, followed by a 20 mL saline flush, as recommended by the most recent guidelines 1. The initial dose of 6 mg is given as a rapid IV push through a large vein, preferably in the antecubital fossa, and the patient's arm should be elevated after administration to facilitate rapid delivery to the heart. If the first dose fails to convert the rhythm within 1-2 minutes, a second dose of 12 mg should be given, and if necessary, a third dose of 12 mg can be administered 1. Adenosine works by temporarily blocking AV nodal conduction, interrupting the reentry circuit responsible for most SVTs. The drug has an extremely short half-life (less than 10 seconds), which makes it ideal for acute conversion but also necessitates rapid administration. Some key points to consider when administering adenosine include:
- Patients should be warned about transient side effects including chest pain, flushing, dyspnea, and a sense of impending doom, which typically resolve within seconds.
- Continuous cardiac monitoring is essential during administration, and resuscitation equipment should be immediately available due to the potential for brief asystole or other arrhythmias.
- Adenosine is safe and effective in pregnancy, with no expected adverse effects to the fetus due to its short half-life 1.
- The medication should be used with caution in patients with asthma, and alternative treatments should be considered in these cases 1.
From the FDA Drug Label
The recommended adenosine injection dose is 0.14 mg/kg/min infused over six minutes (total dose of 0.84 mg/kg)
Table 1 Dosage Chart for Adenosine Injection The nomogram displayed in Table 1 was derived from the following general formula: 0.14 (mg/kg/min) x total body weight (kg) = Infusion rate (mL/min) Adenosine injection concentration (3 mg/mL)
The dose of adenosine for supraventricular tachycardia (SVT) is not explicitly stated in the provided drug labels. However, the recommended dose for adenosine injection is 0.14 mg/kg/min infused over six minutes, with a total dose of 0.84 mg/kg 2 2.
- Key points:
- The dose is administered as a continuous peripheral intravenous infusion.
- The infusion rate can be calculated using the formula: 0.14 (mg/kg/min) x total body weight (kg) = Infusion rate (mL/min), considering an adenosine injection concentration of 3 mg/mL. However, the provided labels do not directly address the dose for SVT.
From the Research
Adenosine Dose for Supraventricular Tachycardia (SVT)
The standard dose of adenosine for SVT is typically administered in a series of escalating doses, starting with 6 mg, followed by 12 mg, and then an additional 12 mg if necessary 3, 4, 5.
Efficacy and Safety
Studies have shown that adenosine is effective in converting SVT to sinus rhythm, with a success rate of around 93% 3. Adenosine has a rapid onset of action and a short half-life, which makes it a safe option for treating SVT 3, 6, 4.
High-Dose Adenosine
In cases where the standard dosing regimen fails to terminate SVT, higher doses of adenosine may be considered. A case report describes the successful use of high-dose adenosine (24 mg and 36 mg) in a patient with refractory SVT 7.
Comparison with Other Treatments
Adenosine has been compared to calcium channel antagonists, such as verapamil, in the treatment of SVT. Studies have shown that adenosine and verapamil are equally effective in converting SVT to sinus rhythm, but adenosine may have a faster onset of action and fewer side effects 6, 4.
Side Effects
Adenosine can cause side effects such as chest discomfort, dyspnea, and flushing, but these are typically short-lived and resolve quickly 3, 6, 4. In rare cases, adenosine may cause more serious side effects, such as hypotension or bronchospasm 4.
Treatment Guidelines
Current treatment guidelines recommend adenosine as first-line therapy for SVT, followed by other agents such as diltiazem or beta blockers if adenosine is unsuccessful 5.