AlbuterolMetered Dose InhalersDry Powder InhalersNebulizers and VaporizersAdministration, InhalationChlorofluorocarbonsAerosol PropellantsPowdersBronchodilator AgentsAerosolsInhalation SpacersAsthmaAnti-Asthmatic AgentsBeclomethasoneBudesonideHydrocarbons, FluorinatedIpratropiumPregnadienediolsEthanolaminesFenoterolTerbutalineRespiratory System AgentsEquipment DesignRespiratory TherapyPulmonary Disease, Chronic ObstructiveForced Expiratory VolumePeak Expiratory Flow RateCross-Over StudiesChlorofluorocarbons, MethaneParticle SizePregnenedionesAdrenergic beta-AgonistsDouble-Blind MethodScopolamine DerivativesAndrostadienesAdrenal Cortex HormonesPatient Education as TopicDrug CombinationsDrug Delivery SystemsChemistry, PharmaceuticalTherapeutic EquivalencyCromolyn SodiumAdrenergic beta-2 Receptor AgonistsLung Diseases, ObstructiveCholinergic AntagonistsHoarsenessPatient ComplianceTechnology, PharmaceuticalGlucocorticoidsInspiratory CapacityMaximal Expiratory Flow RateTreatment OutcomeAnti-Inflammatory AgentsOzone DepletionAtropine DerivativesRespiratory Function TestsSelf Administration