(Summary based on an article by T. Paul and J-P Pfammatter originally published in Pediatric Cardiology, Volume 18, 1997, pages 118-126.)

The most common symptomatic dysrhythmia in children, including infants and adolescents, is paroxysmal supraventricular tachycardia (PSVT). In adults, optimal treatment has been identified as adenosine, which is highly effective (90-100%) against PSVT. In children, the authors from this paper assert that adenosine is also "...an effective, safe drug for the diagnosis and treatment of paroxysmal tachycardias in infants and children."

While the exact function of endogenous adenosine has not been determined, exogenous adenosine has been shown to prolong AV nodal refractoriness and to induce transient AV block. Administered to children via an initial rapid bolus dose of 0.05 mg/kg, followed by 0.5-0.10 mg/kg step doses (maximum dose 0.25-0.30 mg/kg or until tachycardia is terminated), the efficacy of adenosine in children is similar to that demonstrated in adults. In fact, efficacy rates in several clinical trials have shown AV reentrant tachycardia to be terminated in 86% to 100% of pediatric patients treated with adenosine.

A unique characteristic of adenosine is its extremely short half-life of less than ten seconds, which contributes to a short duration (less than 60 seconds) of side effects. Facial flushing, dyspnea and chest pain are side effects that may occur following administration; however, in most patients these effects are mild and transient. In some cases, induction of bronchospasm has been reported; therefore, alternative treatments/methods should be used in patients with reactive airway disease. Although both adenosine and verapamil are clinically proven to be highly effective in the treatment of PSVT, verapamil is contraindicated in patients with ventricular tachycardia or tachycardia with a widened QRS complex, apparent and latent left ventricular dysfunction or concomitant therapy with beta-blockers. Additionally, these authors maintain that while adenosine is safe for children, "...newborns, infants and young children should not be given verapamil." In contrast, they also note that "even if ventricular tachycardia is misdiagnosed as supraventricular tachycardia with bundle branch block" adenosine remains a safe option.

Adenosine is also hemodynamically safe when administered via intravenous bolus . According to the authors, "An initial
10-15 mm Hg increase in systolic and diastolic blood pressure at the time of transient prolongation of AV conduction is followed by a decrease of blood pressure during subsequent tachycardia." Therefore, since adenosine has a half-life of less than ten seconds, its hemodynamic effect is also of short duration.

Overall, because of its "fast onset of action, absence of significant hemodynamic effects, short half-life, and transient duration of side effects...." adenosine is a safe and effective drug for the acute management of pediatric PSVT and should be considered a first-line agent.