Which is stronger albuterol or xopenex

Although mainly consistent with basic findings, clinical studies suggest no overwhelming superiority of levalbuterol over racemic albuterol; however, levalbuterol's effects may be greatest in moderate to severe asthma patients, especially with racemic albuterol overuse.

Recent adoption of the hydrofluoroalkane formulation has narrowed the cost gap between levalbuterol and racemic albuterol metered-dose inhalers, but it remains for the nebulized formulations. Thus, physician selection of these drugs has remained dependent on experience, pharmaceutical knowledge, and established prescribing habits combined with cost factors, formulary structures, and availability, such that racemic albuterol is still used significantly compared with levalbuterol to treat acute asthma exacerbations.

What was the outcome? There was no difference between these agents in any effectiveness outcomes, including asthma scores, FEV 1 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. Bob : While there are a couple of minor limitations to this study, I believe it does get to the right answer. Albuterol is composed of equal parts of a racemic mixture of R- and S-enantiomers; levalbuterol is composed of only the active R-enantiomer. Both agents contain an active ingredient, so there is no good reason why one should outperform the other.

Some have postulated that the inactive S-enantiomer in albuterol may result in unwanted effects; however, this study debunks that theory. Andrea : One limitation of this study is that most of the participants had moderate asthma, raising the question about whether the results would be similar in children with severe asthma. And because of the low hospitalization rate 13 percent , firm conclusions regarding this end point cannot be drawn.

Another limitation is the relatively small sample size, making it possible that, if there was a clinically meaningful difference, there were too few study participants for it to be statistically significant. But I agree with Bob; these are similar drugs and there is no reason why one would outperform the other. Many previous studies suggest that this is the case. Part of this spin is a result of which studies actually get published.

Companies are not knocking down doors to have negative studies published about their drugs. This is called publication bias. Studies are more likely to get submitted for publication if they show a company's drug in a good light. However, if you look at all of the studies submitted to the FDA which I did , levalbuterol turns out to be no better than albuterol e. In fact, plain old albuterol had a superior side effect profile in a number of the studies.

This trend of developing drugs that are simply an isomer of an existing drug is likely to boom as manufacturers attempt to replace drugs with expiring patents; it's all about market share. Just look at esomeprazole Nexium and omeprazole Prilosec.

Bob : With regard to market share, the makers of Xopenex Sepracor Inc. Currently, most of the 52 million annual prescriptions for albuterol are for metered-dose inhalers that contain chlorofluorocarbon CFC propellants. Because of the detrimental effects that CFC has on ozone levels, metered-dose inhalers containing CFC will be not be sold in the United States after Mark : Samples are given to physicians for one reason—marketing.

It has been clearly shown that samples will lead physicians to dispense and later prescribe brand name medications, even if these drugs were not the physician's preferred first-line choice. Andrea : If samples were not good business for the drug companies, the sample cabinet would be empty.

Bob : For me, it's straightforward—since there is no difference in effectiveness or side effects between albuterol and levalbuterol, there is no good reason to choose the more expensive drug, Xopenex, when treating children with moderate asthma. Further, a recent study in adults with severe asthma came to the same conclusion: good old fashioned albuterol works just as well as the new drug, Xopenex, at a fraction of the cost. Andrea : I agree; when switching to new metered-dose inhalers with HFA, go with the most cost-effective drug.

Mark : And do your best to avoid accepting samples—it ultimately costs patients more in the long run. There is no difference between albuterol and levalbuterol in effectiveness or side effects in children with moderate asthma exacerbations. Be prepared for the mandatory switch in metered-dose inhalers to products containing hydrofluoroalkane HFA in place of chlorofluorocarbon CFC by the end of Be aware of publication bias.

S -albuterol promotes contractility through increases in intracellular calcium in airway smooth muscle cells. S -albuterol also enhances airway hyperresponsiveness and promotes eosinophil recruitment and activation in vitro. The R -isomer has been associated with adverse effects that may preclude its use in certain patients. Because beta 2 -receptors are also found outside the lungs, beta 2 -adrenergic agonists can cause tremor, headache, increased heart rate, hypokalemia, and hyperglycemia.

Beta 2 -agonists are only available as inhaled medications, therefore reducing systemic absorption, but these side effects are concentration-dependent and so may still occur at higher doses. Lam et al 17 investigated the heart rate effects of these 2 agents with a prospective, randomized, crossover study.

Patients who required a bronchodilator more often than every 4 hours, required a vasopressor or inotropic therapy, or were maintained on a beta-blocker were excluded from the study. Heart rate was recorded at the end of the second dose and at 5, 10, 15, 30, 60, 90, , , and minutes after the final dose. The authors concluded that there was no clinically significant difference between groups in maximum heart rate increases and that use of LEV was not justified in their population.

Another retrospective chart review performed by Truitt et al 18 investigated the total number of nebulizer treatments required with ALB and LEV. The investigators assessed patient charts from a 6-month period at 1 institution. The only patients excluded were those with a diagnosis of cognitive disturbances or cancer. ALB 2. The mean hospital length of stay LOS was 5. Regression analysis controlling for diagnosis, baseline forced expiratory volume in 1 second FEV 1 , and ipratropium use indicated that LEV was associated with a shorter LOS decreased by 0.

Because this was a retrospective review, the investigators did not consider sample size calculation and power test to be necessary. Patients received 1 of 5 doses of LEV or 1 of 2 doses of ALB every 20 minutes for 3 doses plus prednisone 60 mg or equivalent ; this was followed by a minute observation period. Patients were excluded if they had been hospitalized for asthma within 2 months, had fixed airway disease, or had received ALB in the ED before enrollment.

Patients treated with LEV 0. Patients treated with ALB 2. A comparison of equivalent amounts of the R -isomer in the 2 beta 2 -agonists demonstrated that there were statistically significant differences. LEV 1. LEV 2. Changes in glucose, potassium, and heart rate were proportional to the dose of the R -isomer. Potential limitations of this study included its open-label design and the cohort sizes 12—14 patients each.

Differences in age were also statistically significant among groups. Patients received either LEV 1. A number of major limitations were associated with this study.

First, the study was retrospective and uncontrolled. Comparisons of postdosing efficacy were not made. There were twice as many patients in the ALB group as in the LEV group, and the use of other therapy eg, corticosteroids was not accounted for in the study. The admission rate for patients in the ALB group was also higher than the rate observed in similar studies.

In another study by Nowak et al, 21 the investigators assessed the time to ED discharge in adults presenting with an acute asthma exacerbation who received either LEV or ALB.

This study was a prospective, multicenter, double-blind, parallel-group trial. Patients could receive additional asthma therapy if this was considered necessary by the investigator. All patients were treated with prednisone 40 mg, and during the initial 3-hour treatment period, certain medications were not permitted, including ipratropium, long-acting beta 2 -agonists LABAs , leukotriene modifiers, methylxanthines, corticosteroids other than prednisone 40 mg, and magnesium.

There were 2 evaluation periods in this study: an acute period and a 7- and day follow-up period. The median time to discharge primary outcome was similar for both groups LEV, Subgroup analysis demonstrated a benefit of LEV compared with ALB on FEV 1 and hospital admission rate in patients who were not taking corticosteroids at home, but no difference was observed among patients taking corticosteroids.

No difference was observed between groups for the incidence of adverse effects, including tachycardia. The authors concluded that there is a benefit in using systemic corticosteroids early in therapy and scheduled dosing of beta 2 -agonists in patients with acute exacerbations. A multicenter, randomized, double-blind study published by Milgrom et al 23 compared the efficacy and safety of LEV and ALB in stable asthmatic children.

Patients who had a lower respiratory tract infection within 2 weeks of randomization or had a clinically significant abnormality in electrocardiogram were not included in the study. Patients were treated with LEV 0. The investigators observed no significant difference in the primary outcome of peak percent change from baseline in FEV 1 at 21 days between LEV 0.

No differences were observed among treatment groups on the outcomes of asthma symptom assessment score, symptom-free days, quality-of-life score, rescue medication use, and time to peak improvement in FEV 1. Serum glucose was significantly increased with ALB 2. The authors concluded that smaller doses of LEV led to bronchodilation similar to that of standard-dose ALB in this group of patients.

They recommended that for patients aged 4 to 11 years, the starting dose of LEV should be 0. Treatment with a systemic corticosteroid within 30 days or astemizole within 90 days, a respiratory tract infection within 2 weeks, or life-threatening asthma within 1 year of the study screening were exclusion criteria. Patients were allowed to continue treatment with ipratropium and inhaled corticosteroids if these agents were taken at stable doses before and throughout the study.