Our study compared levalbuterol (LEV) to the combination of racemic albuterol (RAC) and ipratropium bromide (IB) in 140 patients aged 6-18 years presenting to a tertiary hospital Emergency Department with acute asthma and a peak expired flow rate (PEF)<80% predicted. Patients were randomized to: LEV (<or=6 nebs LEV 1.25 mg); or RAC/IB (<or=3 nebs RAC 5.0 mg+IB 0.25 mg followed as needed by <or=3 nebs RAC 5.0 mg). No difference was noted in the study population (mean age 11.6 years and initial mean predicted PEF 49.5%) between LEV (n=72) and RAC/IB (n=68) for study outcomes except for measures of heart rate (HR). Median % HR increase for RAC/IB (26%) exceeded LEV (9%) (p<0.001). In a sample of children with acute asthma and initial mean PEF<50% predicted, LEV was associated with less tachycardia but had no other advantage over RAC combined with IB.