A cumulative dose study of levalbuterol and racemic albuterol administered by hydrofluoroalkane-134a metered-dose inhaler in asthmatic subjects.

BACKGROUND: The short-acting beta(2)-agonists levalbuterol and racemic albuterol are available for administration through a hydrofluoroalkane-134a (HFA) metered-dose inhaler (MDI). OBJECTIVE: This study compared the short-term safety and efficacy of cumulative doses of levalbuterol HFA MDI and racemic albuterol HFA MDI in asthmatic subjects. METHODS: This was a randomized, modified-blind, active-controlled, multicenter, 2-way crossover study. Subjects (n = 49) were randomized to 16 cumulative doses (1x, 2x, 4x, 8x, and 16x) of levalbuterol (45 microg per dose) or racemic albuterol (90 microg per dose) administered over a 2-hour period. After a 7-day washout period, subjects were crossed over to the other treatment. After each dose, safety outcomes and pulmonary function were assessed. RESULTS: Heart rate and (R)-albuterol exposure increased for both racemic albuterol HFA and levalbuterol HFA. For cumulative doses of 8x or greater, racemic albuterol HFA treatment had greater increases in mean heart rate than levalbuterol HFA (least-squares mean [+/- SD] difference at the 8x dose was 2.8 beats/min [95% CI, 0.3-5.3] and at the 16x dose was 3.5 beats/min [95% CI, 0.6-6.4]). (R)-albuterol plasma levels ranged from 10% to 18% higher after racemic albuterol HFA MDI dosing versus after levalbuterol HFA MDI. FEV(1) improvements were similar for both treatments. The relative potencies of the 2 therapies, based on FEV(1), were similar (ratio, 1.1 [90% CI, 0.9-1.2]; Finney method). CONCLUSION: In this study single-day cumulative dosing of asthmatic subjects with levalbuterol HFA MDI or racemic albuterol HFA MDI resulted in similar improvements in FEV(1) and tolerability. Plasma (R)-albuterol levels and mean heart rate were less with levalbuterol HFA MDI.

Topical Trabodenoson Is Neuroprotective in a Rodent Model of Anterior Ischemic Optic Neuropathy (rNAION).

PURPOSE: Nonarteritic anterior ischemic optic neuropathy (NAION) is the leading cause of sudden optic nerve-related vision loss currently without effective treatment. We evaluated the neuroprotective potential of ocular (topical) delivery of trabodenoson, a selective A1 receptor mimetic, in a rodent model of NAION (rNAION). METHODS: Daily topical delivery of 3% trabodenoson or vehicle administered in both eyes 3 days prior to rNAION induction and for 21 days post induction. Retinal appearance and optic nerve head (ONH) edema was evaluated using spectral-domain optical coherence tomography (SD-OCT). Retinal function was evaluated before and after induction by ganzfeld electroretinography (ERG). Brn3a(+) retinal ganglion cells (RGCs) were quantified by stereology. Axonal ultrastructure was evaluated by electron microscopy. RESULTS: Trabodenoson-treated eyes had significantly reduced optic nerve (ON) edema compared with vehicle-treated eyes (ANOVA, P < 0.05). Electrophysiologically, there was a nonsignificant trend toward b-wave and oscillatory potential (OP) preservation in the trabodenoson-treated eyes. RGC counts were higher in trabodenoson-treated eyes compared to vehicle (74% versus 47% of the contralateral eye; two-tailed t-test; P = 0.01), as were ON axons. No overt morphologic differences in cell inflammation were observed between vehicle- and trabodenoson-treated ONHs, but trabodenoson-treated ONHs revealed increased expression of astrocyte-related neuroprotective responses. CONCLUSIONS: Trabodenoson preserves RGCs in the rodent NAION model. While previous clinical trials focused on trabodenoson's ocular antihypertensive effect, our data suggest trabodenoson's primary target may be both the retina and ONH. Selective adenosine A1 agonists may prove an appropriate neuroprotective adjunctive for ischemia-related ON diseases such as NAION and glaucoma. TRANSLATIONAL RELEVANCE: RGC and ON neuroprotection in ischemic neuropathies may be achievable by topical administration of A1 adenosine agonists rather than by simply relying on intraocular pressure reduction.

Trabodenoson, an Adenosine Mimetic With A1 Receptor Selectivity Lowers Intraocular Pressure by Increasing Conventional Outflow Facility in Mice.

Purpose: To evaluate the relationship between the IOP-lowering effect of trabodenoson and the associated structural and functional changes in the trabecular meshwork (TM). Methods: Six independent cohorts of young and aged mice were exposed to three different topical once-a-day formulations of trabodenoson and eyes were compared to those treated with placebo drops. IOP was measured daily just before drug administration using rebound tonometry. Outflow facility was measured in enucleated eyes. Flow patterns and morphology of conventional outflow tissues were monitored using tracer beads and standard histology, respectively. In parallel, three-dimensional human TM tissue constructs (3D-HTM) were grown and used in experiments to test effect of trabodenoson on the expression of collagen IV, fibronectin, matrix metalloproteinase (MMP)-2 and MMP-14 plus MMP-2 activity. Results: Topical administration of trabodenoson significantly lowered IOP on every day tested, up to 7 days. After 2 days of treatment, outflow facility increased by 26% in aged mice and 30% overall (young and aged mice), which was significantly different from vehicle (P < 0.05). Outflow facility was 15% higher than controls after 7 days of treatment (P = 0.07). While gross morphology was not affected by treatment, the intensity of tracer bead distribution increased by day 7 (P = 0.05). Parallel experiments in 3D-HTM showed that trabodenoson treatment significantly increased MMP-2 activity and MMP-14 abundance, while decreasing fibronectin and collagen IV expression. Conclusions: Trabodenoson alters ECM turnover by TM cells and increases conventional outflow facility, which accounts for its ability to lower IOP in young and aged mice.

Nebulized arformoterol in patients with COPD: a 12-week, multicenter, randomized, double-blind, double-dummy, placebo- and active-controlled trial.

OBJECTIVE: The aim of this study was to assess the efficacy and tolerability of nebulized arformoterol tartrate (a selective, long-acting beta(2)-adrenergic agonist that is the [R,R] isomer of formoterol) and salmeterol xinafoate versus placebo in patients with chronic obstructive pulmonary disease (COPD). METHODS: This 12-week, multicenter, randomized, double-blind, double-dummy, placebo- and active-controlled trial was conducted at 60 centers across the United States. Male and female patients aged >or=35 years with physician-diagnosed COPD received arformoterol (15 microg BID, 25 microg BID, or 50 microg QD via nebulizer), salmeterol (42 microg BID via metered dose inhaler), or placebo. Pulmonary function was assessed by spirometry; dyspnea, by the Transitional Dyspnea Index (TDI); and health status, by the St. George's Respiratory Questionnaire (SGRQ). Adverse events (AEs) were assessed by site personnel at all clinic visits (screening, first dose at week 0, and at weeks 3, 6, 9, 12, and follow-up). COPD exacerbations were defined as worsening respiratory status requiring a change in medication or an unscheduled provider visit. RESULTS: A total of 717 patients received study medication. The demographic composition of all treatment arms was similar. The mean age was 62.9 years, 58% were men, and mean baseline forced expiratory volume in 1 second (FEV(1)) was 1.2 L (41% predicted). Mean improvement in trough FEV(1) over 12 weeks was significantly greater with all 3 arformoterol doses (15 microg BID, +16.9%; 25 microg BID, +18.9%; 50 microg QD, +14.9%) and for salmeterol (+17.4%) relative to placebo (+6.0%; P < 0.001). There were significantly greater improvements in the mean percentage change in FEV(1) AUC(0-12h) from the predose value over 12 weeks (15 microg BID, 12.7%, 25 microg BID, 13.9%, 50 microg QD, 18.9%; salmeterol, 9.8%) versus placebo (2.7%; P

Evaluation of levalbuterol metered dose inhaler in pediatric patients with asthma: a double-blind, randomized, placebo- and active-controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of levalbuterol metered dose inhaler (MDI) in children aged 4-11 years (n = 173). RESEARCH DESIGN AND METHODS: Multicenter, randomized, double-blind 28-day study of QID levalbuterol 90 microg, racemic albuterol 180 mug, and placebo (2:1:1 ratio). Serial spirometry was performed on Days 0, 14, and 28. The primary endpoint was the double-blind average peak percent (%) change in FEV(1) from visit pre-dose; the primary comparison was with placebo. Secondary endpoints included the area under the FEV(1) percent change from pre-dose curve and peak % predicted FEV(1). Safety endpoints included adverse events, laboratory tests, rescue medication use, and electrocardiograms. RESULTS: Levalbuterol significantly improved the least square mean peak percent change in FEV(1) compared with placebo (levalbuterol 25.6% +/- 1.3% [p < 0.001]; racemic albuterol 21.8% +/- 1.8% [p = ns]; placebo 16.8% +/- 1.9%). Results for levalbuterol were similar for the other spirometry endpoints (p < 0.05 vs. placebo). No levalbuterol-treated patients had a peak percent change in FEV(1) < 10% (compared with 15.8% of racemic albuterol-treated patients and 30.3% of placebo-treated patients). The incidence of adverse events was 43.4% for levalbuterol, 56.4% for racemic albuterol, and 51.4% for placebo. The rate of discontinuation was 1.3% for levalbuterol, 2.6% for racemic albuterol, and 8.6% for placebo. The rate of asthma attacks (10.5%, 12.8%, 14.3%, respectively) was similar among treatments. Levalbuterol and racemic albuterol both reduced rescue medication use (p < 0.01 vs. placebo) and produced changes in ventricular heart rate and QT(c-F) that were similar to placebo. CONCLUSIONS: In this study, levalbuterol administered via MDI significantly improved airway function in comparison with placebo in asthmatic children aged 4-11 years with a safety profile that was similar to placebo.

A Randomized Phase 1 Dose Escalation Study to Evaluate Safety, Tolerability, and Pharmacokinetics of Trabodenoson in Healthy Adult Volunteers.

PURPOSE: To investigate the safety, tolerability, and pharmacokinetics of trabodenoson, a highly selective adenosine mimetic targeting the adenosine A1 receptor. METHODS: In Part 1, 60 healthy adult volunteers were randomized to 14 days of twice-daily topical monocular application of placebo or trabodenoson (200, 400, 800, 1,600, 2,400, or 3,200 µg). In Part 2, 10 subjects were randomized to placebo or 8 escalating doses of bilateral trabodenoson (total daily doses: 1,800-6,400 µg). RESULTS: The incidence of treatment-related adverse events in Part 1 was similar in the trabodenoson (27.8%) and placebo (25.0%) groups. Most were mild in intensity. The most common adverse events (AEs) for trabodenoson and placebo were headache (25.0% vs. 33%, respectively) and eye pain (11.1% vs. 4.2%, respectively). Ocular AEs were infrequent (16.7% and 17.9%, respectively), were self-limited, lasted <24 h, and were typically mild in intensity. The most common ocular AE was eye pain (9.5% and 3.6%, respectively), with a single observation of ocular hyperemia (200 µg trabodenoson). Trabodenoson was rapidly absorbed [median time to maximum concentration (tmax): ∼0.08 to 0.27 h] and eliminated (t½: 0.48-2.0 h), with no evidence of drug accumulation. Systemic exposure to topical trabodenoson was dose related but not dose proportional, with a plateau effect at doses ≥2,400 mg per eye. No clinically significant treatment-related systemic AEs were observed, and increasing systemic exposure had no effect on heart rate or blood pressure. CONCLUSIONS: Ocular doses of trabodenoson up to 3,200 µg per eye were safe and well tolerated in the eye and resulted in no detectable systemic effects in healthy adult volunteers.

A Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of 2 and 4 Weeks of Twice-Daily Ocular Trabodenoson in Adults with Ocular Hypertension or Primary Open-Angle Glaucoma.

PURPOSE: To evaluate the safety and ocular hypotensive efficacy of 4 trabodenoson doses administered twice daily over 14 or 28 days in subjects with ocular hypertension or primary open-angle glaucoma (POAG). METHODS: In this multicenter, randomized, double-masked, placebo-controlled, dose-escalation Phase 2 study, patients received unilateral topical twice-daily trabodenoson (50, 100, or 200 mcg) or placebo for 14 days, or 500 mcg trabodenoson or placebo for 28 days. Ocular and systemic safety and tolerability were assessed by examinations, clinical and laboratory studies. Intraocular pressure (IOP) was assessed using Goldmann tonometry. RESULTS: Trabodenoson was well tolerated; no clinically meaningful ocular or systemic side effects were identified. Trabodenoson produced a dose-dependent IOP reduction. IOP reductions in the 500 mcg group were significantly greater than placebo at all time points at Day 28. Mean IOP reductions from diurnal baseline ranged from -3.5 to -5.0 mmHg with a mean change of -4.1 mmHg in the 500 mcg group compared -1.0 to -2.5 mmHg with a mean change of -1.6 mmHg for the placebo group, and the Day 28 drop was significantly greater than at Day 14 (P = 0.0163) indicating improvement in IOP lowering with longer treatment time. IOP remained significantly reduced 24 h after the final 500 mcg dose (P = 0.048). CONCLUSION: Twice-daily ocular doses of trabodenoson, from 50 to 500 mcg, were well tolerated and showed a dose-related decrease in IOP that was statistically significant and clinically relevant at 500 mcg in patients with ocular hypertension or POAG.

Evaluation of the safety and efficacy of levalbuterol in 2-5-year-old patients with asthma.

The purpose of this study was to evaluate the safety and efficacy of single-isomer (R)-albuterol (levalbuterol, LEV) in children aged 2-5 years. Children aged 2-5 years (n = 211) participated in this multicenter, randomized, double-blind study of 21 days of t.i.d. LEV (0.31 mg or 0.63 mg without regard to weight), racemic albuterol (RAC, 1.25 mg for children <33 pounds (lb); 2.5 mg for children >/=33 lb), or placebo (PBO). Endpoints included adverse-event (AE) reporting, safety parameters, peak expiratory flow (PEF), the Pediatric Asthma Questionnaire(c) (PAQ), and the Pediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ). Baseline disease severity was generally mild in all groups, as defined by PAQ scores that ranged from 6.3-7.3 on a scale of 0-27 and 1.5 days/week of uncontrolled asthma. After treatment, the PAQ decreased in all groups (P = NS). In the subset of subjects able to perform PEF (51.7%), all active treatments improved in-clinic PEF after the first dose (mean +/- SD: PBO, 1.4 +/- 20.8; LEV 0.31 mg, 12.4 +/- 12; LEV 0.63 mg, 16.7 +/- 15.4; RAC, 18.0 +/- 16.5 l/min; P < 0.01). PACQLQ measurements improved more than the minimally important difference only in the LEV-treated groups, and were significant in children <33 lb (P < 0.05). Asthma exacerbations occurred primarily in children >/=33 lb, and one serious asthma exacerbation occurred in the 2.5-mg RAC group. RAC and LEV 0.63 mg, but not LEV 0.31 mg or placebo, led to significant increases in ventricular heart rate. In this study of levalbuterol in children aged 2-5 years with asthma, LEV was generally well-tolerated, and in children able to perform PEF, led to significant bronchodilation compared with placebo.

Effect of nebulized arformoterol on airway function in COPD: results from two randomized trials.

RATIONALE: Arformoterol, a single isomer long-acting beta(2)-agonist, was developed as an inhalation solution for the maintenance treatment of bronchoconstriction in COPD. METHODS: The pulmonary function efficacy of nebulized arformoterol (15 micro g BID, 25 micro g BID, 50 micro g QD) and salmeterol MDI (42 micro g BID) versus placebo was assessed in 1456 subjects (mean FEV(1) 1.2L, mean predicted 41%). Data were pooled from 2 identical, 12-week, double-blind, randomized trials. The percent change in trough FEV(1), percent change in FEV(1) average AUC((0 - 12 hrs)) and peak percent change FEV(1) from predose were analyzed. RESULTS: Improvement in trough FEV(1) averaged over 12 weeks was greater for arformoterol and salmeterol versus placebo (mean differences from placebo [95% CI] arformoterol-15 micro g BID: 11.4% [8.4, 14.3]; 25 micro g BID: 15.4% [12.2, 18.6]; 50 micro g QD: 10.9% [7.9, 13.9]); salmeterol: (11.6% [8.8, 14.4]). Greater improvements versus placebo occurred after the first dose (mean differences between arformoterol and placebo for trough FEV(1): 13-19%; FEV(1) AUC((0 - 12 hrs)): 19-24%; peak percent change: 20-25%) and at week 12 (trough FEV(1): 10-13%; FEV(1) AUC((0 - 12 hrs)): 6-13%; peak percent change: 7-14%); all 95% CIs excluded zero. Increases in FEV(1) AUC((0 - 12 hrs)) and peak percent change were greater for arformoterol than for salmeterol (95% CIs excluded zero). After 12 weeks, 78-87% of arformoterol subjects had > or = 10% increases in FEV(1) from pre-dose (56% salmeterol, 44% placebo); the median time to response was 3-13 minutes (142 minutes salmeterol). CONCLUSIONS: In these trials, COPD subjects administered nebulized arformoterol demonstrated significant and sustained improvement in lung function over 12 weeks.

Arrhythmias in patients with chronic obstructive pulmonary disease (COPD): occurrence frequency and the effect of treatment with the inhaled long-acting beta2-agonists arformoterol and salmeterol.

Beta-adrenergic stimulation may increase heart rate and the potential for cardiac arrhythmias. The effect of inhaled long-acting beta2-agonists (LABAs) on these outcomes was evaluated in patients with chronic obstructive pulmonary disease (COPD) in 2 double-blind randomized clinical trials. The pretreatment arrhythmia occurrence frequency in these patients was also described. In this analysis, 24-hour Holter monitoring data were pooled from 2 identically designed Phase III trials. Patients were randomized to LABA treatment or placebo for 12 weeks: a) nebulized arformoterol 15 microg BID, b) 25 microg BID, or c) 50 microg QD; d) salmeterol metered dose inhaler 42 microg BID; or e) placebo. The 24-hour Holter monitoring was performed pretreatment and at Weeks 0 (first day of dosing), 6, and 12. We assessed the proportion of patients with each of 4 arrhythmias: atrial tachycardia, atrial fibrillation/flutter, and "nonsustained"; (4-10 beats) and "sustained"; (>10 beats) ventricular tachycardia. There were 5226 Holter recordings in 1429 treated patients. At baseline, there was a low frequency of occurrence of atrial fibrillation/flutter (0.1%), nonsustained ventricular tachycardia (3.1%), and >10 beat ventricular tachycardia (0.3%). Atrial tachycardia occurred frequently (41.8%). The proportion of patients with treatment-emergent atrial tachycardia ranged from 27% to 32% and was non-significantly higher, by approximately 2%-5% (p = 0.70), in the LABA groups compared with the placebo group. The rates of the other more serious arrhythmias did not increase with LABA treatment and were similar to placebo. All treatment groups (LABA and placebo) had consistent small decreases from baseline in mean 24-hour and maximum hourly heart rate. In conclusion, in this large cohort of COPD patients with no or stable cardiac comorbidities, a high proportion ( approximately 40%) of patients were observed to have atrial tachycardia before treatment, which increased by 2%-5% with LABA treatment. More serious arrhythmias were infrequent and did not increase with inhaled LABA therapy. LABA administration did not increase mean heart rate.

Population pharmacokinetics of (R)-albuterol and (S)-albuterol in pediatric patients aged 4-11 years with asthma.

OBJECTIVE: To characterize the population pharmacokinetics (PK) of (R)- and (S)-albuterol in pediatric asthmatics using a model that supports a sparse blood sampling strategy. METHODS: The data for this analysis were collected from patients enrolled in a randomized, double-blind, multicenter, placebo- and active-controlled study evaluating the safety and efficacy of levalbuterol in asthmatic children aged 4-11 years. Patients received either levalbuterol 0.31 mg, levalbuterol 0.63 mg, racemic albuterol 1.25 mg, or racemic albuterol 2.5 mg via nebulizer. Separate population pharmacokinetic models were developed for (R)- and (S)-albuterol using the NOMNEM((R)) computer program. Covariate models were developed to identify significant predictors of inter-patient variability. RESULTS: A total of 995 samples and 262 patients were used for the (R)-albuterol population PK model while a total of 496 samples and 128 patients were used for the (S)-albuterol population PK model. The apparent clearance of (R)-albuterol was much more rapid than that of (S)-albuterol (approximately four-fold higher), and the apparent volume of distribution was much larger for (R)-albuterol (in part due to pre-systemic metabolism) than for (S)-albuterol (approximately four-fold higher). CONCLUSIONS: In this study of pediatric patients, the models were able to demonstrate using two to four samples per patient that the apparent clearance and volume of distribution of (R)-albuterol were several fold higher than that of (S)-albuterol. The pharmacokinetics of (R)-albuterol were similar after administration of levalbuterol or racemic albuterol and were linear over the examined dose range (0.31-0.63 mg nebulized dose). The presence of (S)-albuterol did not significantly alter the pharmacokinetics of (R)-albuterol, suggesting that effects of (S)-albuterol may be due to the intrinsic pharmacology of this isomer.

Long-term safety study of levalbuterol administered via metered-dose inhaler in patients with asthma.

BACKGROUND: Previous studies have raised concerns regarding the safety of regular use of beta2-agonists for treating asthma. Few studies have explored the safety of at least 1 year of use of racemic albuterol, and none have examined long-term dosing of levalbuterol. OBJECTIVE: To examine the long-term safety of levalbuterol hydrofluoroalkane (HFA) vs racemic albuterol HFA administered via metered-dose inhaler (MDI) in patients with stable asthma. METHODS: Patients with mild to moderate asthma (mean forced expiratory volume in 1 second [FEVI], 68.3% of predicted) 12 years or older participated in a multicenter, parallel-group, open-label study. Patients were randomized to levalbuterol HFA MDI (90 microg; 2 actuations of 45 microg; n = 496) or racemic albuterol HFA MDI (180 microg; 2 actuations of 90 microg; n = 250) for 52 weeks of 4 times daily dosing. The primary end point was the incidence of postrandomization adverse events. Asthma exacerbations and pulmonary parameters were also assessed. RESULTS: The overall incidence of adverse events was similar for levalbuterol (72.0%) and racemic albuterol (76.8%). Rates of beta-mediated adverse events, serious adverse events, and discontinuations because of adverse events were low (<15%) and were comparable between groups. Rates of asthma adverse events for levalbuterol and racemic albuterol were 18.3% and 19.6%, respectively. Mean percentage of predicted FEV1 improved after dosing and was stable for both groups. CONCLUSION: In this trial, up to 52 weeks of regular use of levalbuterol HFA MDI or racemic albuterol HFA MDI was well tolerated, and no deterioration of lung function was detected during the study period.

Evaluation of the efficacy and safety of levalbuterol in subjects with COPD.

The efficacy and safety of nebulized levalbuterol in adults with chronic obstructive pulmonary disease (COPD) was evaluated in this multicenter, randomized, double-blind, parallel design study. Randomized subjects (n = 209) received levalbuterol (LEV) 0.63 mg or 1.25 mg, racemic albuterol (RAC) 2.5 mg, or placebo (PBO) TID for 6 weeks. Serial spirometry was completed in-clinic after study drug alone (weeks 0, 2, and 6) or in combination with ipratropium bromide 0.5 mg (week 4). The primary endpoint was the averaged FEV1 AUC(0-8 hrs) over weeks 0, 2 and 6 compared with placebo. Other endpoints included rescue medication use, safety parameters, COPD exacerbations, and global evaluations. All active treatments demonstrated improvements in the percent change in FEV1 AUC(0-8 hrs) over the double-blind period and at each visit vs PBO (p < 0.05). Rescue medication use vs. baseline (doses/day) changed over time: PBO +0.38 +/- 3.3; LEV 0.63 mg +0.07 +/- 3.3; LEV 1.25 mg -0.84 +/- 3.8 (p = 0.02 vs. RAC); RAC +0.97 +/- 2.5. The overall rate of adverse events was PBO 56.4%, LEV 0.63 mg 56.6%, LEV 1.25 mg 67.3%, and RAC 65.4%. Protocol-defined COPD exacerbations occurred in all groups (PBO 12.7%, LEV 0.63 mg 11.3%; LEV 1.25 mg 18.4%; RAC 21.2%). Withdrawals due to COPD exacerbations were significantly higher in the RAC group compared with PBO (PBO 0%; LEV 0.63 mg 1.9%; LEV 1.25 mg 4.1%; RAC 9.6% p = 0.01 vs. PBO). In this study, levalbuterol treatment in subjects with COPD was generally well tolerated, produced significant bronchodilation compared with PBO, and improved clinical control of COPD as evidenced by reductions in rescue medication use compared with PBO and/or RAC.

A comparison of levalbuterol with racemic albuterol in the treatment of acute severe asthma exacerbations in adults.

UNLABELLED: This multicenter, randomized, double-blind trial compared nebulized levalbuterol (Lev) and racemic albuterol (Rac) in the treatment of acute asthma. METHODS: Adults with acute asthma exacerbations (FEV(1) 20%-55% predicted) received prednisone and either Lev (1.25 mg, n = 315) or Rac (2.5 mg, n = 312). Nebulized treatments were administered every 20 minutes in the first hour, then every 40 minutes for 3 additional doses, then as necessary for up to 24 hours. The primary end point was time to meet discharge criteria. Secondary end points included changes in lung function and hospitalization rates. A subset of 160 patients had plasma (S)-albuterol concentrations determined at study entry. RESULTS: Time to meet discharge criteria did not differ between the 2 treatments. FEV(1) improvement was greater following Lev compared with Rac, both after dose 1 and cumulatively over the entire treatment period (dose 1 in intent to treat [ITT] group: Lev 0.50 +/- 0.43 L, Rac 0.43 +/- 0.37 L; P = .02), particularly among the 60% of patients not on recent steroid therapy (dose 1: Lev 0.58 +/- 0.47 L, Rac 0.44 +/- 0.37 L; P < .01), and patients whose entry (S)-albuterol concentrations were in the highest quartile of those measured. A small and similar proportion of Lev-treated (7.0%) and Rac-treated (9.3%) patients required hospitalization (P = .28). Among patients not on steroids, fewer Lev- than Rac-treated patients required admission (3.8% vs 9.3%, P = .03), as was also the case for patients with high plasma (S)-albuterol concentrations. Asthma relapses (5% in 30 days) were lower than in previous reports and did not differ between groups. CONCLUSIONS: This study suggests that early, regular nebulized beta(2)-agonist and systemic corticosteroid therapy may reduce hospitalization and relapse rates in patients with acute severe asthma. Lev was well tolerated and compared favorably with Rac in improving airway function, particularly in those who were not on inhaled or oral corticosteroids and in those who had high plasma (S)-albuterol concentrations at presentation.