Metered Dose InhalersNebulizers and VaporizersDry Powder InhalersAsthmaAdministration, InhalationChlorofluorocarbonsAerosol PropellantsBronchodilator AgentsAlbuterolPowdersAerosolsBeclomethasoneInhalation SpacersAnti-Asthmatic AgentsFenoterolIpratropiumBudesonideHydrocarbons, FluorinatedTerbutalineRespiratory System AgentsForced Expiratory VolumeEthanolaminesEquipment DesignPregnenedionesPeak Expiratory Flow RateChlorofluorocarbons, MethaneCross-Over StudiesDouble-Blind MethodAndrostadienesAdrenergic beta-AgonistsHoarsenessCromolyn SodiumAtropine DerivativesParticle SizePulmonary Disease, Chronic ObstructivePregnadienediolsDrug Delivery SystemsRespiratory TherapyAdrenal Cortex HormonesLungLung Diseases, ObstructiveGlucocorticoidsChemistry, PharmaceuticalTechnetiumTechnology, PharmaceuticalVital CapacityTreatment OutcomeBiological AvailabilityPatient Education as TopicAnti-Inflammatory AgentsScopolamine DerivativesAsthma, Exercise-InducedDrug Administration ScheduleRespiratory Function TestsDrug CombinationsBronchiAdrenergic beta-2 Receptor AgonistsHydrocortisoneTherapeutic EquivalencyPatient ComplianceCholinergic AntagonistsSpirometryDose-Response Relationship, DrugRespiratory SoundsBronchial HyperreactivityMethacholine ChlorideMaximal Expiratory Flow RateBronchoconstrictor AgentsBronchial SpasmBronchoconstrictionInspiratory CapacityDrug Therapy, CombinationSelf AdministrationMedication AdherenceOzone DepletionPatient PreferenceAsthma, OccupationalSeverity of Illness IndexQuestionnairesInhalationAllergensTime FactorsSelf CareNedocromilAirway ObstructionBronchitisHypersensitivity