This is a PI-initiated study taking place only at UCLA, sponsored by Sunovion. The investigators plan to enroll about 20 subjects who are at least 40 years old and have Chronic Obstructive Pulmonary Disease (COPD). The purpose of this study is to compare the effectiveness of Brovana and Serevent in helping relieve COPD symptoms. Specifically, the investigators are looking at how much and for how long the two drugs can open up the small airways in the lungs. This will be done with breathing tests on all subjects, and with high resolution CT scans on subjects who agree to this optional part of the study. Half of subjects will take Brovana (arformoterol tartrate inhalation solution) for 2 weeks and then Serevent (salmeterol xinafoate inhalation powder) for 2 weeks; the other half will take Serevent the first two weeks and Brovana the second two weeks. All subjects will also take Spiriva (tiotropium) and will be provided with albuterol for immediate relief of symptoms. After a Screening Visit to determine eligibility, subjects will be randomly assigned to receive Brovana or Serevent for the first 2 weeks, complete Test Visit 1, then receive the other study drug for 2 weeks, and finally complete Test Visit 2. Visits will include questionnaires, review of health and medications, and breathing tests before and after taking the study drug. Subjects who agree to be in the sub-study will also undergo CT scans before and after taking the study drug at both test visits.

Inclusion Criteria:

• Age >=40 years

• History of smoking >=20 pack-years of cigarettes

• Be using medically acceptable birth-control measures if a female of child-bearing potential

• Be willing to withhold any existing short or long-acting bronchodilators for the appropriate time period prior to each test day. Use of inhaled corticosteroids is not exclusionary, but will be maintained at a constant level throughout the study.

• Must be willing and able to perform spirometry, slow vital capacity, plethysmography, DLCO, and 6 minute walk after appropriate instruction.

• Informed consent

• At the screening visit:

  • Post-albuterol FEV1/FVC <LLN (Hankinson)
  • Post-albuterol FEV1 <70%% and >=30 % predicted (Hankinson)
  • An increase in FEV1 after 4 puffs albuterol sulfate HFA of at least 5% and 50ml

Exclusion Criteria:

• Presence of other clinically significant illnesses or condition that might interfere with the study, including but not limited to uncontrolled hypertension, cardiovascular disease, cardiac arrhythmia, diabetes, hyperthyroidism, seizure disorder or any history of pheochromocytoma
• History of asthma (in the opinion of the investigator)
• A COPD exacerbations within the past 2 months requiring oral corticosteroids or hospitalization.
• Continuous oxygen therapy greater than 12 hours per day
• Subjects with a body mass index less than 15 or greater than 38
• Known allergy or contradiction to albuterol, arformoterol, salmeterol, tiotropium or prior significant adverse reactions to other beta agonists or ipratropium.
• Hypersensitivity to milk protein. Bloating or gas from lactose is not an exclusion.
• Inability to withhold other adrenergic drugs (salmeterol, arformoterol, formoterol, albuterol etc.) for an appropriate duration before each visit.
• Ongoing need for drugs which might potentiate hypokalemia (xanthine derivatives (theophylline), steroids, non-potassium sparing diuretics (unless in fixed combination with potassium sparing diuretic)
• Ongoing need for drugs which might cause QTc prolongation (MAO inhibitors, tricyclic antidepressants, cardiac anti-arrhythmics Class Ia (e.g., disopyramide, procainamide, quinidine), or class III (e.g., amiodarone, dofetilide, ibutilide, sotalol), terfenadine, astemizole, mizolastin and any other drug with potential to significantly prolong the QT interval.)
• Ongoing need for beta-blockers (selective or non-selective)
• Use of phenothizines (thioridizine), or other drugs that may interact with arformoterol, salmeterol or albuterol for the duration of the study. Washout of greater than seven half-lives of the drug prior to the study.
• History of angle closure glaucoma, symptomatic prostatic hypertrophy or bladder neck obstruction.
• Investigational drugs within 30 days
• Affiliation with the Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine
• Pregnancy, breastfeeding, planning to become pregnant during study, or woman of childbearing potential unwilling to use adequate contraception