Transcript Slide 1
Chapter 26 Respiratory System Drugs and Antihistamines Overview • Airway basics • Respiratory drugs • Impact of exercise on respiratory drugs • Impact of respiratory drugs on exercisers • Impact of respiratory drugs on performance • Potential complications Airway Basics • Bronchial tree – Trachea – Bronchi – Bronchioles – Alveoli Airway Basics • Cellular respiration – Gas exchange that occurs at alveoli • Ventilation – Movement of air in & out of the lungs • Upper respiratory tract – Conditions air (temperature & Airway Basics • Autonomic nervous system – Controls rate and depth through smooth muscle contraction/relaxatio n – Acetylcholine (cholinergic receptors) – Norepinephrine Airway Basics • Cholinergic receptors – Medicinal blockers used for allergies & colds – Cause decreased salivation, dry mouth, and gastric activity • Adrenergic receptors – Alpha (alpha-1 & alpha-2): peripheral blood vessels – Beta (beta-1 & beta-2): cardiac/smooth mm and respiratory tract respectively Airway Basics • In cases of asthma and bronchoconstriction, passages become constricted • May be congenital • May be allergy or pollutant related • Worldwide asthma pharmaceutical Airway Basics Airway Basics Normal Acute Fatal Asthma Chronic Severe Asthma Airway Basics • Effects worsened in cold, dry air • Exercise-induced bronchoconstriction (EIB) – AKA: • Exercise-induced asthma • Exercise-induce bronchospasm • Postexercise Airway Basics • Asthma “attacks” may be triggered by inflammatory response (mucus production to rid irritant) and/or bronchospasm (bronchiole constriction to limit irritant) • Typically managed medicinally – Control meds vs. “rescue” meds – Metered Dose Inhaler (MDI) Respiratory Drugs • Bronchodilators – Used to combat bronchoconstriction • Anti-inflammatories – Steroidal – Non-steroidal • Medicine type – Oral • More consistent, but slower – MDI • Faster acting, but often used improperly Respiratory Drugs • Beta-2 agonists classified according to duration of action – Short acting • Used prn • Proventil, Ventolin – Long lasting • Controlling drugs • Serevent • OTC asthma meds may affect cardiac function Respiratory Drugs • Refractory period – 50% of athletes w/ EIB experience symptom-free period for 1-2 hours after asthma exacerbation – Athletes with known refractory period may use it to their advantage Respiratory Drugs • Sympathomimetics – Albuterol (Proventil, Ventolin tablet, syrup Rx) • Use ~ 15 min. before exercise for EIB – Salmeterol Xinafoate (Serevent aerosol Rx) • Use ~ 30-60 min. before exercise for EIB Respiratory Drugs • Corticosteroid Inhalants – Either prevent narrowing or relax smooth muscle of lung; NOT used for acute asthma – Used to prevent or reduce frequency of chronic bronchial asthma attacks (when not controlled by bronchodilators or nonsteroid medications) Respiratory Drugs • Common Corticosteroid Inhalants – Beclomethasone Diproprionate (Beclovent Rx) – Flunisolide (AeroBid Rx) – Side Effects: Dry mouth, hoarseness, wheezing, rash Respiratory Drugs • Intranasal Steroids – Work by shrinking swollen nasal tissue and reducing inflammation – Used for seasonal allergies or hay fever involving inflammation of mucous membranes of nasal passages Respiratory Drugs • Common Intranasal Steroids – Beclomethasone Diproprionate (Beconase, Vancenase Rx) – Fluticasone Proprionate (Flonase aerosol Rx) Impact of Exercise on Respiratory Drugs • May hinder effects of histamine receptor antagonists • Normal training response is bronchodilation – Exercise may augment effects of bronchodilators • Many respiratory drugs are flowlimited – Dexamethasone, theophilline, terbutaline – Unlikely that increased duration of action Impact of Respiratory Drugs on Exercisers • Beta agonists and anti-inflammatory agents have little to no impact on exercise HR • Bronchodilators have minimal impact on exercise HR • Some studies have actually demonstrated decreases in FEV and VO2 Impact of Respiratory Drugs on Performance • Exercise limiters – Cardiac output & VO2 • Not ventilation, alveolar gas diffusion, or other lung functions • Little to no effects with localized dosing as used to treat respiratory conditions – Findings relatively consistent among both trained and untrained participants – Isolated studies have indicated Impact of Respiratory Drugs on Performance • No change in RPE • Increases in mm strength have been noted with albuterol and clenbuterol • Theophilline effects similar to caffeine in many respects – Increases in strength and power have been noted • Psychological effect? – 98% of triathletes claimed to be asthmatic in 1999 Potential Complications • Side effects – Nervousness – Restlessness – Dizziness – Sleeplessness – Dry mouth – Appetite changes – Throat irritation – Rebound vasodilation (nasal sprays) Potential Complications • Theophylline shows greatest risk…most others considered extremely safe • Decreased BMD in women and children who use chronically – Can be offset with ability to exercise • NCAA allows inhalation use (banned systemically) • USOC/IOC allow use with written Oxygen • • • • Hypoxia Administration of oxygen Side effects Cautions Copyright © 2007 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 26 Respiratory Stimulants • Caffeine • Theophylline • Carbon dioxide inhalations Copyright © 2007 by Thomson Delmar Learning. ALL RIGHTS RESERVED. 27 Review Bronchodilators • Relax smooth muscles of bronchial tree – Relieve bronchospasm – Increase vital capacity of lungs • Uses – Acute respiratory conditions – COPD Edited by Dr. Ryan Lambert-Bellacov 28 Bronchodilators • Sympathomimetics (adrenergics) – Metered dose inhalers – Breath-actuated inhales • Parasympatholytics (anticholinergics) • Xanthines • Patient education Edited by Dr. Ryan Lambert-Bellacov 29 Mucolytics and Expectorants • Mucolytics – Liquefy pulmonary secretions • Expectorants – Increase secretions, reduce viscosity, and expel sputum Edited by Dr. Ryan Lambert-Bellacov Mucolytics and Expectorants • Adequate fluid intake • Side effects • Contraindications or caution Edited by Dr. Ryan Lambert-Bellacov Antitussives • • • • • • Prevent coughing When used Side effects Contraindications Interactions Patient education Edited by Dr. Ryan Lambert-Bellacov Antihistamines • Competitively antagonize the histamine1 receptor sites • Not curative • Treat symptoms of allergies • Adjunctive treatment of anaphylactic reactions • First and second generation drugs Edited by Dr. Ryan Lambert-Bellacov Decongestants • Constrict blood vessels in respiratory tract • Used for short-term basis • Side effects • Contraindications or extreme caution • Interactions • Patient education Edited by Dr. Ryan Lambert-Bellacov Smoking Cessation Aids • Lower level of nicotine – Behavior modification for smoking cessation • Nicorrette gum • Nicoderm patch • Nicotrol inhaler Edited by Dr. Ryan Lambert-Bellacov