Bronchodilator Agents: Agents that cause an increase in the expansion of a bronchus or bronchial tubes.Albuterol: A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.Ipratropium: A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Terbutaline: A selective beta-2 adrenergic agonist used as a bronchodilator and tocolytic.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Nebulizers and Vaporizers: Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.Spirometry: Measurement of volume of air inhaled or exhaled by the lung.Scopolamine Derivatives: Analogs or derivatives of scopolamine.Metaproterenol: A beta-2 adrenergic agonist used in the treatment of ASTHMA and BRONCHIAL SPASM.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Peak Expiratory Flow Rate: Measurement of the maximum rate of airflow attained during a FORCED VITAL CAPACITY determination. Common abbreviations are PEFR and PFR.Fenoterol: An adrenergic beta-2 agonist that is used as a bronchodilator and tocolytic.Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Atropine Derivatives: Analogs and derivatives of atropine.Bronchoconstriction: Narrowing of the caliber of the BRONCHI, physiologically or as a result of pharmacological intervention.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Pulmonary Disease, Chronic Obstructive: A disease of chronic diffuse irreversible airflow obstruction. Subcategories of COPD include CHRONIC BRONCHITIS and PULMONARY EMPHYSEMA.Aerosols: Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.Metered Dose Inhalers: A small aerosol canister used to release a calibrated amount of medication for inhalation.Adrenergic beta-Agonists: Drugs that selectively bind to and activate beta-adrenergic receptors.Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Bronchial Provocation Tests: Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.Adrenergic beta-2 Receptor Agonists: Compounds bind to and activate ADRENERGIC BETA-2 RECEPTORS.Inhalation Spacers: A variety of devices used in conjunction with METERED DOSE INHALERS. Their purpose is to hold the released medication for inhalation and make it easy for the patients to inhale the metered dose of medication into their lungs.Clemastine: A histamine H1 antagonist used as the hydrogen fumarate in hay fever, rhinitis, allergic skin conditions, and pruritus. It causes drowsiness.Methacholine Chloride: A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Bronchi: The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.Chlorofluorocarbons: A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, blowing agents, cleaning fluids, solvents, and as fire extinguishing agents. They have been shown to cause stratospheric ozone depletion and have been banned for many uses.Respiratory Therapy: Care of patients with deficiencies and abnormalities associated with the cardiopulmonary system. It includes the therapeutic use of medical gases and their administrative apparatus, environmental control systems, humidification, aerosols, ventilatory support, bronchopulmonary drainage and exercise, respiratory rehabilitation, assistance with cardiopulmonary resuscitation, and maintenance of natural, artificial, and mechanical airways.Ethanolamines: AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.Inspiratory Capacity: The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration. It is the sum of the TIDAL VOLUME and the INSPIRATORY RESERVE VOLUME. Common abbreviation is IC.Respiratory Therapy Department, Hospital: Hospital department which is responsible for the administration of diagnostic pulmonary function tests and of procedures to restore optimum pulmonary ventilation.Maximal Expiratory Flow Rate: The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.Antitussive Agents: Agents that suppress cough. They act centrally on the medullary cough center. EXPECTORANTS, also used in the treatment of cough, act locally.Cholinergic Antagonists: Drugs that bind to but do not activate CHOLINERGIC RECEPTORS, thereby blocking the actions of ACETYLCHOLINE or cholinergic agonists.Bronchial Spasm: Spasmodic contraction of the smooth muscle of the bronchi.Theophylline: A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-CYCLIC NUCLEOTIDE PHOSPHODIESTERASE that degrades CYCLIC AMP thus potentiates the actions of agents that act through ADENYLYL CYCLASES and cyclic AMP.Nedocromil: A pyranoquinolone derivative that inhibits activation of inflammatory cells which are associated with ASTHMA, including eosinophils, neutrophils, macrophages, mast cells, monocytes, and platelets.Indans: Aryl CYCLOPENTANES that are a reduced (protonated) form of INDENES.Anti-Asthmatic Agents: Drugs that are used to treat asthma.Bronchoconstrictor Agents: Agents causing the narrowing of the lumen of a bronchus or bronchiole.Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Forced Expiratory Flow Rates: The rate of airflow measured during a FORCED VITAL CAPACITY determination.Amino Alcohols: Compounds possessing both a hydroxyl (-OH) and an amino group (-NH2).Cough: A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.Aminophylline: A drug combination that contains THEOPHYLLINE and ethylenediamine. It is more soluble in water than theophylline but has similar pharmacologic actions. It's most common use is in bronchial asthma, but it has been investigated for several other applications.Functional Residual Capacity: The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.Glycopyrrolate: A muscarinic antagonist used as an antispasmodic, in some disorders of the gastrointestinal tract, and to reduce salivation with some anesthetics.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Adrenal Cortex HormonesRespiratory Sounds: Noises, normal and abnormal, heard on auscultation over any part of the RESPIRATORY TRACT.Beclomethasone: An anti-inflammatory, synthetic glucocorticoid. It is used topically as an anti-inflammatory agent and in aerosol form for the treatment of ASTHMA.Respiratory Care Units: The hospital unit in which patients with respiratory conditions requiring special attention receive intensive medical care and surveillance.ButylaminesBudesonide: A glucocorticoid used in the management of ASTHMA, the treatment of various skin disorders, and allergic RHINITIS.Parasympatholytics: Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Nasal Decongestants: Drugs designed to treat inflammation of the nasal passages, generally the result of an infection (more often than not the common cold) or an allergy related condition, e.g., hay fever. The inflammation involves swelling of the mucous membrane that lines the nasal passages and results in inordinate mucus production. The primary class of nasal decongestants are vasoconstrictor agents. (From PharmAssist, The Family Guide to Health and Medicine, 1993)Bronchitis: Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.Aerosol Propellants: Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Oscillometry: The measurement of frequency or oscillation changes.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Residual Volume: The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.Dyspnea: Difficult or labored breathing.Tephrosia: A plant genus of the family FABACEAE that contains tephrorin, tephrosone, and C-prenylflavonoids.Quinolones: A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.Total Lung Capacity: The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.Muscarinic Antagonists: Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.Bronchial Hyperreactivity: Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.Helium: Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)Lung Compliance: The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Pharmaceutical Solutions: Homogeneous liquid preparations that contain one or more chemical substances dissolved, i.e., molecularly dispersed, in a suitable solvent or mixture of mutually miscible solvents. For reasons of their ingredients, method of preparation, or use, they do not fall into another group of products.Tachyphylaxis: Rapidly decreasing response to a drug or physiologically active agent after administration of a few doses. In immunology, it is the rapid immunization against the effect of toxic doses of an extract or serum by previous injection of small doses. (Dorland, 28th ed)Histamine: An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.Drug Labeling: Use of written, printed, or graphic materials upon or accompanying a drug container or wrapper. It includes contents, indications, effects, dosages, routes, methods, frequency and duration of administration, warnings, hazards, contraindications, side effects, precautions, and other relevant information.Cromolyn Sodium: A chromone complex that acts by inhibiting the release of chemical mediators from sensitized mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack.Amaranthus: A plant genus, in the family AMARANTHACEAE, best known as a source of high-protein grain crops and of Red Dye No. 2 (AMARANTH DYE). Tumbleweed sometimes refers to Amaranthus but more often refers to SALSOLA.Drug Packaging: Containers, packaging, and packaging materials for drugs and BIOLOGICAL PRODUCTS. These include those in ampule, capsule, tablet, solution or other forms. Packaging includes immediate-containers, secondary-containers, and cartons. In the United States, such packaging is controlled under the Federal Food, Drug, and Cosmetic Act which also stipulates requirements for tamper-resistance and child-resistance. Similar laws govern use elsewhere. (From Code of Federal Regulations, 21 CFR 1 Section 210, 1993) DRUG LABELING is also available.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Bronchitis, Chronic: A subcategory of CHRONIC OBSTRUCTIVE PULMONARY DISEASE. The disease is characterized by hypersecretion of mucus accompanied by a chronic (more than 3 months in 2 consecutive years) productive cough. Infectious agents are a major cause of chronic bronchitis.Procaterol: A long-acting beta-2-adrenergic receptor agonist.Drug Tolerance: Progressive diminution of the susceptibility of a human or animal to the effects of a drug, resulting from its continued administration. It should be differentiated from DRUG RESISTANCE wherein an organism, disease, or tissue fails to respond to the intended effectiveness of a chemical or drug. It should also be differentiated from MAXIMUM TOLERATED DOSE and NO-OBSERVED-ADVERSE-EFFECT LEVEL.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Histamine Antagonists: Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.Asthma, Exercise-Induced: Asthma attacks following a period of exercise. Usually the induced attack is short-lived and regresses spontaneously. The magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).Isoproterenol: Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Ephedrine: A phenethylamine found in EPHEDRA SINICA. PSEUDOEPHEDRINE is an isomer. It is an alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used for asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists.Racepinephrine: A racemic mixture of d-epinephrine and l-epinephrine.Plethysmography, Whole Body: Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)Air Filters: Barriers used to separate and remove PARTICULATE MATTER from air.Lung Volume Measurements: Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.Leukotriene Antagonists: A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.Prostanoic Acids: 2-Octylcyclopentaneheptanoic acids. The family of saturated carbon-20 cyclic fatty acids that represent the parent compounds of the prostaglandins.Nonprescription Drugs: Medicines that can be sold legally without a DRUG PRESCRIPTION.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Placebos: Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.Bronchiolitis: Inflammation of the BRONCHIOLES.Receptors, Adrenergic, beta-2: A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). The adrenergic beta-2 receptors are more sensitive to EPINEPHRINE than to NOREPINEPHRINE and have a high affinity for the agonist TERBUTALINE. They are widespread, with clinically important roles in SKELETAL MUSCLE; LIVER; and vascular, bronchial, gastrointestinal, and genitourinary SMOOTH MUSCLE.Expiratory Reserve Volume: The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration. Common abbreviation is ERV.Respiration Disorders: Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.Myrtus: A plant genus of the family MYRTACEAE. Members contain PHYTOHEMAGGLUTININS.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Glucocorticoids: A group of CORTICOSTEROIDS that affect carbohydrate metabolism (GLUCONEOGENESIS, liver glycogen deposition, elevation of BLOOD SUGAR), inhibit ADRENOCORTICOTROPIC HORMONE secretion, and possess pronounced anti-inflammatory activity. They also play a role in fat and protein metabolism, maintenance of arterial blood pressure, alteration of the connective tissue response to injury, reduction in the number of circulating lymphocytes, and functioning of the central nervous system.Respiratory Physiological Phenomena: Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.Plethysmography: Recording of change in the size of a part as modified by the circulation in it.Acute Disease: Disease having a short and relatively severe course.S-Nitrosoglutathione: A sulfur-containing alkyl thionitrite that is one of the NITRIC OXIDE DONORS.Oxygen Inhalation Therapy: Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)Methacholine Compounds: A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.Phosphodiesterase 4 Inhibitors: Compounds that specifically inhibit PHOSPHODIESTERASE 4.Aminopyridines: Pyridines substituted in any position with an amino group. May be hydrogenated, but must retain at least one double bond.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Thiorphan: A potent inhibitor of membrane metalloendopeptidase (ENKEPHALINASE). Thiorphan potentiates morphine-induced ANALGESIA and attenuates naloxone-precipitated withdrawal symptoms.Management Information Systems: Systems designed to provide information primarily concerned with the administrative functions associated with the provision and utilization of services; also includes program planning, etc.Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.Hypersensitivity, Immediate: Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Intermittent Positive-Pressure Breathing: Application of positive pressure to the inspiratory phase of spontaneous respiration.CyclopropanesPhosphodiesterase Inhibitors: Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.