Asthma

• Asthma


  A chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways

  
• Asthma


  • Can cause difficulty breathing
  • An incurable disease but manageable
  • Swollen or inflamed walls → airways extremely sensitive to irritations → increases susceptibility to an allergic reaction
  • Asthma attacks may last from few minutes to several hours
  • Occurs frequently at night
  • 1 of 35 people suffer from asthma (⅔ of this population may develop asthma before reaching age of 5)
  • Asthma is a hyperactive response of bronchi and bronchioles to some agent which causes cells to contract
• Agents of asthma


  • house dust
  • mites
  • grain dust
  • pollen
  • grass
  • smoke
  • hair
  • molds
  • feathers
  • polluted air
  • perfumes
  • polish
  • chemical vapors
  • foods
  • sudden temperature changes
  • physical exertion
  • weather
  • excitement
• Signs and symptoms of asthma


  • Wheezing
  • Coughing
  • Breathing difficulty
  • Tightness in the chest
  • Worsening symptoms at night
  • Worsening symptoms due to cold air
  • Symptoms while exercising
  • Symptoms after exposure to allergens
  • Runny nose
  • Sinus infections
  • Acid reflux disease
  • Psychological stress
  • Sleep apnea
• Causes of asthma


  • Allergies
  • Tobacco smoke
  • Obesity
  • Pregnancy
  • Stress
  • Genes
  • Atopy (e.g. eczema, allergic rhinitis, allergic conjunctivitis)
  • Environmental (microorganisms, ingestion of drugs, psychological)
• Atopy


  General class of hypersensitivity that affects different parts of body that do not come in contact with allergens
• Goals of asthma medications


  • To relieve acute episodic attacks of asthma
  • To reduce the frequency of attacks, and nocturnal awakenings
• Types of asthma medications

  • Bronchodilators
  • Anti-inflammatory
• Bronchodilators


  • Short-acting B2-agonists
  • Antimuscarinics
  • Xanthines
• Anti-inflammatory medications


  • Long acting B2 agonists
  • Glucocorticoids (steroids)
  • Leukotriene receptor antagonists
  • Mast cell stabilizers
• Beta-2 Adrenoreceptor Agonists (Short-acting)


  • Inhibit mediator release from mast cells
  • Increase mucus clearance
  • Mechanism of action: beta-2 receptor → stimulates adenylyl cyclase → increased cAMP → smooth muscle relaxation (bronchodilation)
• Types of Beta-2 Adrenoreceptor Agonists (Short-acting)


  • Non-selective B2-Agonists
  • Selective B2-Agonists
• Non-selective B2-Agonists


  • Stimulate both beta-1 (heart) and beta-2 (smooth muscle) receptors
  • Increased heart rate and other sympathetic effects occur in addition to bronchodilation
  • Tachycardia and cardiac arrhythmias
• Non-selective B2-Agonists


  • Epinephrine
  • Isoproterenol
  • Metaproterenol
• Selective B2-Agonists


  • Drug of choice for acute attacks of asthma
  • Cause bronchodilation without tachycardia
• Selective B2-Agonists


  • Salbutamol (albuterol, Ventolin)
  • Terbutaline
• Antimuscarinics


  • Less effective than B2 agonists
  • Mechanism of action: antagonize binding of acetylcholine to muscarinic receptors (promotes contraction of airway smooth muscle and increase mucous secretion)
• Antimuscarinics


  • Ipratropium (Atrovent)
  • Tiotropium
• Xanthines/Methylxanthines


  • Purine derivatives
  • Phosphodiesterase inhibitor
  • Inhibit the bronchoconstrictive action of adenosine and activate histone deacetylases which may result in decreases in the transcription of proinflammatory genes
  • Inhibit the release of proinflammatory agents, like HISTAMINE, from a variety of inflammatory cells
  • A drug for primary apnea of prematurity in which the absence of respiratory effort lasts longer than 20 seconds in newborn infants
  • Initially administered intravascularly then orally
  • Crosses the placenta (teratogenic)
• Xanthines/Methylxanthines


  • Caffeine (coffee)
  • Theobromine (cocoa)
  • Theophylline (tea)
• Beta-2 Adrenoreceptor Agonists (Long-acting, Selective)


  • Used for nocturnal asthma
  • May increase the risk of a severe asthma attack, unless they are used in combination with an inhaled corticosteroid
• Beta-2 Adrenoreceptor Agonists (Long-acting, Selective)


  • Salmeterol
  • Formoterol
  • Indacaterol
• Glucocorticoids (Steroids)


  • Mechanism of action: inhibits the enzyme phospholipase A2 (precursor of leukotrienes, prostaglandins, platelet activating factor)
  • Used alone or combined with beta-agonists
• Types of Glucocorticoids (Steroids)


  • Inhaled corticosteroids
  • Systemic corticosteroids
• Inhaled corticosteroids


  First-line therapy for persistent asthma in adults and children
• Inhaled corticosteroids


  • Beclomethasone
  • Budesonide
  • Flunisolide
  • Fluticasone
• Systemic corticosteroids


  • Travel throughout the body before reaching the airway
  • Results in more side effects and more serious side effects than with inhaled corticosteroids
  • Considered as a first-line treatment for acute asthma exacerbations

  
• Systemic corticosteroids (Oral)


  • Prednisone
  • Prednisolone
  • Methylprednisolone
  • Betamethasone
  • Dexamethasone
  • Hydrocortisone
• Systemic corticosteroids (Parenteral)


  • Triamcinolone (kenalog)
• Leukotriene Receptor Antagonists


  • Zafirlukast: for treatment of chronic asthma
  • Montelukast: prevent wheezing, difficulty breathing, chest tightness, and coughing caused by asthma; treat symptoms of seasonal and perennial allergic rhinitis (HAY FEVER)
  • Pranlukast: more effective in patients with moderate or severe asthma who are not treated with oral steroids
• Mast Cell Stabilizers


  Mechanism of action: Interferes with the antigen-antibody reaction to release mast cell mediators; Inhibits mast cell degranulation (release of inflammatory mediators in response to specific antigens)
• Mast Cell Stabilizers


  • Cromolyn
  • Nedocromil
• Reliever Inhalers (Short-acting Bronchodilators)


  • Contain bronchodilator medicines
  • Ease symptoms when you are breathless, wheezy or tight-chested
  • Medicine relaxes the muscle in the airways
• Reliever Inhalers


  • Salbutamol
  • Terbutaline
• Preventer Inhalers (Steroid Inhalers)


  • Usually contain a steroid medicine
  • Taken everyday to prevent symptoms from developing
  • Reduce the inflammation in the airways
  • Usually taken twice per day
• Preventer Inhalers


  • Beclometasone
  • Budesonide
  • Ciclesonide
  • Fluticasone
  • Mometasone
• Long-acting Bronchodilator Inhalers


  • Steroid + long-acting bronchodilator
  • Work for up to 12 hours after taking each dose
  • May be advised in addition to a steroid inhaler if symptoms are not fully controlled by the steroid inhaler alone
• Long-acting Bronchodilator Inhalers


  • Fostair® (Formoterol and Beclomethasone)
  • Seretide® (Salmeterol and Fluticasone)
  • Symbicort® (Formoterol and Budesonide)
• Inhaler Devices


  • Pressurized metered dose inhalers (MDIs)
  • Breath-activated inhalers
  • Inhalers with spacer devices
  • Nebulizers
• Long-term Asthma Control Medications


  • Long-acting beta agonists: Opens the airways and reduces inflammation; May increase the risk of a severe asthma attack (take them only in combination with an inhaled corticosteroid)
  • Inhaled medications: Salmeterol, Formoterol