This is my last post on this.
Does Xopenex Have Fewer Side Effects than Albuterol?
Albuterol is well-known to cause certain side effects, including muscle tremors, jitteriness, palpitations and increased heart rate. Early studies on Xopenex suggested that because far less medicine was needed to achieve the same benefit as albuterol, fewer side effects would occur. In addition, it was initially thought that the S-albuterol isomer was primarily responsible for many of the albuterol side effects, and therefore Xopenex, which does not contain the S-albuterol isomer, would cause few side effects.
Recent studies suggest, however, that the side effects of Xopenex are equivalent to albuterol, since it is actually the R-albuterol isomer that is responsible for the albuterol side effects. The S-albuterol isomer is inert, meaning is does not contribute to side effects. The package insert for Xopenex states that the rate of the above mentioned side effects are similar for equivalent doses of Xopenex and albuterol.
Albuterol (ALB) is a 50:50 racemic mixture of the (R)- and (S)-isomers of albuterol, whereas levalbuterol (LEV) contains only the (R)-isomer. The (S)-isomer is considered inactive and has demonstrated increased inflammatory stimuli in vitro. Studies have compared the efficacy and side effect profiles of these 2 agents in the clinical setting. Randomized, controlled trials with adequate sample size generally have demonstrated no significant differences between LEV and ALB on the outcomes of efficacy, occurrence of adverse effects, and hospital admissions for adults and children. At this time, the use of LEV instead of ALB is not strongly supported by the literature. (Formulary. 2009;44:108118.) - See more at:
http://formularyjournal.modernmedic...rsus-levalbuterol-pediat#sthash.fMNbasGF.dpuf
For children with acute asthma exacerbations, does levalbuterol work better or have fewer side effects than albuterol?
This study is a prospective randomized trial of 129 children two to 14 years of age who presented to the emergency department with an acute exacerbation of asthma. One half of the children received nebulized albuterol, and the other half received levalbuterol. The doses chosen were weight based, and participants were eligible to receive up to five nebulization treatments.
What was the outcome? There was no difference between these agents in any effectiveness outcomes, including asthma scores, FEV1 measures, number of nebulizations required, respiratory rates, pulse oximetry readings, length of emergency department care, or hospitalization rates (Table 1).
Levalbuterol has been promoted to have fewer side effects than albuterol. But were fewer side effects noted with this agent? Absolutely not
Table 1
Outcomes and Side Effects of Albuterol (Proventil) vs. Levalbuterol (Xopenex)
OUTCOMES/SIDE EFFECTS ALBUTEROL (N = 64) LEVALBUTEROL (N = 65)
Median change in pulse rate*
After first nebulization +8 bpm +9 bpm
After third nebulization +21 bpm +22 bpm
After fifth nebulization +18 bpm +18 bpm
Median change in respiratory rate*
After first nebulization 2 2
After third nebulization 4 4
After fifth nebulization 4 5
Median change in pulse oximetry*
After first nebulization +1 +1
After third nebulization +1 +1
After fifth nebulization 1 +1
Side effects
Tremulousness 21 (33%) 24 (37%)
Nausea and vomiting 11 (17%) 5 (8%)
Headache 4 (6%) 8 (12%)
Lightheadedness 3 (5%) 9 (14%)
bpm = beats per minute.
* Median changes reflect differences from baseline.
Albuterol (n = 58), levalbuterol (n=59).
Albuterol (n = 17), levalbuterol (n = 16).
§ One child receiving racemic albuterol had tachycardia (more than 200 bpm), and one child receiving levalbuterol had an elevated temperature (100.4°F [38°C]) before discharge.
Adapted with permission from Qureshi F, Zaritsky A, Welch C, Meadows T, Burke BL. Clinical efficacy of racemic albuterol versus levalbuterol for the treatment of acute pediatric asthma. Ann Emerg Med. 2005;46(1):3334.
Direct from the Xopenex insert shows no difference with tachycardia.
Table 3: Adverse Events Reported in a 4-Week, Controlled Clinical Trial in Adolescents ≥12 years old
Percent of Patients
Body System
Placebo Xopenex 1.25 mg Xopenex0.63 mg Racemic albuterol2.5 mg
Cardiovascular System
Tachycardia 0 2.7 2.8 2.7
These are just a few of the studies out there that show there really is no difference.
