What is the preferred choice between Xopenex (levalbuterol) and albuterol in patients with tachycardia?

From the Guidelines

Levalbuterol (Xopenex) is generally preferred over albuterol in patients with tachycardia. This preference is based on the fact that levalbuterol is the R-isomer of albuterol and produces bronchodilation with potentially fewer cardiovascular side effects, including less tachycardia, as noted in guidelines such as those from the Journal of Allergy and Clinical Immunology 1. The key differences between albuterol and levalbuterol lie in their isomeric composition, with levalbuterol containing only the therapeutically active R-isomer, which may reduce the risk of tachycardia and other adrenergic side effects associated with the S-isomer found in albuterol.

When considering the management of patients with tachycardia, the potential for exacerbating this condition with medication is a critical factor.

• Levalbuterol's dosing via nebulizer typically ranges from 0.63 mg to 1.25 mg every 6-8 hours.
• The metered-dose inhaler delivers 45-90 mcg per puff, with 1-2 puffs every 4-6 hours as needed. In contrast, albuterol contains both R and S isomers, and the S-isomer has been associated with increased adrenergic side effects without contributing significantly to bronchodilation, as discussed in the context of asthma management 1.

However, it's crucial to consider that while levalbuterol may offer theoretical advantages, individual patient response varies, and the clinical significance of these differences may be modest in many patients. Additionally, cost considerations are relevant, as levalbuterol is typically more expensive than albuterol, which may affect treatment decisions when the cardiovascular benefit is not substantial. Ultimately, the choice between levalbuterol and albuterol in patients with tachycardia should be guided by the patient's specific clinical profile, including the severity of their tachycardia, response to previous treatments, and other comorbid conditions.

From the FDA Drug Label

The incidence of certain systemic beta-adrenergic adverse effects (e.g., tremor, nervousness) was slightly less in the Xopenex 0. 63 mg group compared with the other active treatment groups. Changes in heart rate 15 minutes after drug administration and in plasma glucose and potassium 1 hour after drug administration on day 1 and day 29 were clinically comparable in the Xopenex 1.25 mg and racemic albuterol 2. 5 mg groups (see Table 4). Changes in heart rate and plasma glucose were slightly less in the Xopenex 0. 63 mg group compared with the other active treatment groups (see Table 4). Table 3: ... Tachycardia 0 2.7 2.8 2.7 Table 4: Mean Changes from Baseline Heart Rate at 15 Minutes and Glucose and Potassium at 1 Hour after First Dose (Day 1) in Adults and Adolescents ≥12 years old ... Xopenex 0.63 mg, n=72 2.4 ... Xopenex 1.25 mg, n=73 6.9 ... Racemic albuterol 2.5 mg, n=74 5.7

The preferred choice between Xopenex (levalbuterol) and albuterol in patients with tachycardia is Xopenex 0.63 mg, as it has a slightly lower incidence of tachycardia (2.8% vs 2.7%) and a smaller increase in heart rate (2.4 bpm vs 5.7 bpm and 6.9 bpm) compared to albuterol and Xopenex 1.25 mg, respectively 2. However, the clinical significance of these small differences is unknown.

From the Research

Comparison of Albuterol and Xopenex (Levalbuterol) in Patients with Tachycardia

• The choice between Xopenex (levalbuterol) and albuterol in patients with tachycardia depends on various factors, including the severity of the condition and the patient's response to treatment.
• A study published in 2011 3 found that nebulized albuterol and ipratropium did not cause significant tachycardia or tachyarrhythmias in critically ill adult patients, and substitution of levalbuterol for albuterol to avoid tachycardia and tachyarrhythmias was unwarranted.
• Another study published in 2003 4 found that short-term use of nebulized albuterol and levalbuterol was associated with similar changes in heart rate in intensive care patients with or without baseline tachycardia.

Safety and Efficacy of Levalbuterol and Albuterol

• A review published in 2014 5 found that there was limited evidence on the safety of levalbuterol compared to albuterol in patients with tachyarrhythmias, and further research was needed to determine the most efficacious and safe β-2 receptor agonists in this population.
• A study published in 2000 6 found that levalbuterol provided significant bronchodilatory activity and was well tolerated, with less marked effects on heart rate and potassium than racemic albuterol.
• A multicenter, randomized, open-label study published in 2008 7 found that levalbuterol and racemic albuterol had similar effects on symptom outcomes and health status in hospitalized patients with acute asthma or COPD, but levalbuterol required significantly fewer total nebulizations.

Key Findings

• Levalbuterol and albuterol have similar effects on heart rate in patients with or without baseline tachycardia 4.
• Levalbuterol may have a more favorable safety profile than albuterol in terms of cardiac side effects 6.
• Further research is needed to determine the most efficacious and safe β-2 receptor agonists in patients with tachyarrhythmias 5.