L3 Respiratory System PDF - University of Western Australia

DENT3005 Respiratory system Sheetal Maria Rajan [email protected]  Learning Outcomes Broad Objective: Explain how various respiratory drugs can affect dental practice and how these situations can be managed. Specific Medications Covered:...

DENT3005 Respiratory system Sheetal Maria Rajan [email protected]  Learning Outcomes Broad Objective: Explain how various respiratory drugs can affect dental practice and how these situations can be managed. Specific Medications Covered: Asthma COPD  Respiratory Medications Relievers SABA (Short-acting β2 agonist) LABA (Long-acting β2 agonist with Rapid onset) Preventers ICS (Inhaled Corticosteroids) Leukotriene Modifiers Mast Cell Stabilizers Add on Therapy LABA Theophylline Anti-immunoglobulin (IgE) – Omalizumab Anti-interleukin-5 (IL5) - Mepolizumab LAMA (Long-acting muscarinic antagonist) Asthma A chronic condition that inflames and narrows the airways in the lungs Can affect people of all ages Symptoms: coughing, wheezing, shortness of breath, and chest tightness  Asthma attacks can be divided into two phases: the early phase and the late phase. These phases reflect the timing and types of inflammatory responses in the airways after exposure to an allergen or irritant. Symptoms: Clinical Wheezing, Shortness of breath, Chest tightness, Persistent Wheezing, Prolonged Shortness of presentation Coughing breath, Continued Chest tightness, Ongoing Coughing Treatment: SABAs – albuterol (relax the bronchial IC, LABAs, Leukotriene modifiers, in severe muscles) cases systemic corticosteroids Chronic Obstructive Pulmonary Disease (COPD) Chronic inflammatory lung disease- causes obstructed airflow from the lungs Symptoms: breathing difficulty, cough, mucus production, wheezing Typically caused by long-term exposure to irritating gases- cigarette smoke People with COPD- increased risk of developing heart disease, lung cancer and other conditions Two most common conditions that contribute to COPD: Emphysema Chronic bronchitis Chronic bronchitis – inflammation of the lining of bronchial tubes, which carry air to and from the air sacs (alveoli) of the lungs Emphysema- the alveoli at the end of the smallest air passages (bronchioles) of the lungs are destroyed Pharmacokinetics of Inhalers Short-acting β2 Agonist (SABA) Relaxes airway smooth muscle By stimulating β2 adrenergic receptors → Increases cAMP Act quickly (within mins) to open the airways Used as rescue inhalers to provide immediate relief Examples: Salbutamol, Terbutaline  Short-acting Muscarinic Antagonist (SAMA) Relaxes airway smooth muscle induced by acetylcholine-induced post-ganglionic cholinergic nerves. Block M3 muscarinic receptor Rapid bronchodilation (15-30 mins) Used for acute relief of bronchospasm in asthma and COPD, often in combination with SABAs for enhanced effect Examples: Ipratropium Bromide  Long-acting β2 Agonist (LABA) Prolonged bronchodilation ~12-24 hours Monotherapy and in combination with inhaled corticosteroids Long acting: Salmeterol, Formoterol Ultra long acting: Indacaterol, Olodaterol, Vilanterol  Long-acting Muscarinic Antagonist (LAMA) Administration: Once daily [Tiotropium, Umeclidinium] or twice daily [Aclidinium, Glycopyrronium] Block muscarinic receptors in the airways, preventing bronchoconstriction and reducing mucus production For long-term control of COPD and sometimes asthma, in combination with other medications  Leukotriene Modifiers Reduce airway hyper- responsiveness, eosinophil levels, and exhaled nitric oxide They block the action of leukotrienes – chemicals in the immune system that cause inflammation, bronchoconstriction, and mucus production Taken orally- once a day Examples: Montelukast, Zafirlukast Mast Cell Stabilizers Stabilize plasma membranes of mast cells Prevent degranulation and release of histamine, leukotrienes, and other substances that cause airway inflammation Not used for acute bronchodilatory properties Example: Chromoglycate, Nedocromil  Inhaled Corticosteroids (ICS) Anti-inflammatory Reduce bronchial hyper-responsiveness Improve symptoms Used daily to control/prevent chronic symptoms & reduce frequency of exacerbations Examples: Beclometasone, Budesonide, Fluticasone, Mometasone, and Ciclesonide  Antigen- presenting cells  Theophylline Inhibits phosphodiesterase (PDE) enzymes – leading to an increase in cAMP levels in bronchial smooth muscle Elevated Camp levels – relaxation of the bronchial muscles (bronchodilation) Methylxanthine derivative IV or Oral Used to treat airway diseases (~for over 70 years) Relatively high doses required – lead to adverse drug reaction Use declined as inhaled β2 Agonists became more prevalent Anti-inflammatory effects in asthma and COPD at lower concentrations Concerns: Low therapeutic window, drug interactions  Medical history considerations – Past history of severe exacerbations, previous intubation, previous admission of ICU, hospitalization, history of SABA, history of CVD, history and withdrawal of corticosteroids Patient factors of airway obstruction – dementia, Implications psychiatric disease, psychological issues May not tolerate supine position for a long period of time – reduced lung capacity, impaired ventilation, for increased work of breathing, exacerbation of symptoms, circulatory concerns Possible oxygen therapy? – enhanced oxygen supply Dentistry (COPD/asthma patients), reduce anxiety and discomfort, support for compromised breathing Aspirin-containing compounds should be avoided – use NSAIDs Opiates can cause bronchial constriction – may interact with bronchodilators/corticosteroids; use NSAIDs Implications for Dentistry (Continued.) COPD patients: Hypoxic conditions can affect oral health and wound healing Medications and physical factors can cause difficulty breathing through the mouth Dry mouth (Xerostomia) + Decreased saliva production – Anticholinergics + β2 Agonists Inhaled corticosteroids - Oral candidiasis [Rinse mouth after inhaling, regular brushing]  Use of Oral NSAIDs in Uncontrolled Asthma Concerns: - Inhibition of cyclooxygenase (COX) enzymes - Overproduction of cysteinyl leukotrienes (CysLT) - Increased type 2 eosinophilic inflammation Leading to increased bronchoconstriction and worsen asthma Management: Inhaled corticosteroids with or without long-acting β2 agonists Woo, S. D., Luu, Q. Q., & Park, H. S. (2020). NSAID-Exacerbated Respiratory Disease (NERD): From Pathogenesis to Improved Care. Frontiers in pharmacology, 11, 1147.  NSAID-Exacerbated Respiratory Disease (NERD) Moderate-to-severe asthma Higher prevalence of chronic rhinosinusitis/nasal polyps NSAIDs like aspirin/ibuprofen exacerbate respiratory symptoms Management: Inhaled corticosteroids with/without long-acting β2 agonists; acetaminophen is often recommended for pain management as it does not have the same respiratory effects as NSAIDs