T2 L15: Respiratory pharmacology

• What are the bronchodilators you need to know?

  adrenergic agonists: Salbutamol, Salmeterol

  muscarinic antagonists: Tiotropium

  Short acting anti muscarinic (SAMA): Ipratropium

  Methlylxanthines: Aminophylline
• What are the anti-inflammatory drugs you need to know?

  steroids:

  • oral: Prednisolone
  • Inhaled: Beclometasone
• What are some inhaled drug devices?

  Pressurised metered dose inhalers (pMDIs)

  Dry-powder inhalers
• How do pMDIs work?

  deep exhale → inhale and puff → hold breath for slow ten count → exhale slowly → wait one minute before seconds puff

  use spacer/aerochamber

  use HCFC - carbon footprint
• How do Dry-powder inhalers work?

  usually only inhalation, not a puff
• What are the properties of Salbutamol?

  
  

  mechanism of action: SABA (short acting beta agonist): binds beta 2 receptors in lungs → activate adenylate cyclase → produce cAMP → relaxation of smooth muscle

  duration: short acting (begin immediately, 3-5 hour duration)

  Routes: inhaled or nebuliser for higher dose; IV (rare)

  Use: asthma and COPD

  
• What are the properties of Salmeterol?

  mechanism: LABA (long-acting beta-adrenoceptor agonist)

  duration: long acting (begin 2-30 mins, last 10-12 hrs)

  Routes: inhaled

  Uses: asthma (requiring long-term treatment), persistent COPD

  
• What are the properties of Tiotropium?

  Mechanism: LAMA (long acting muscarinic antagonist), inhibits M3 receptors in smooth muscle → bronchodilation

  Duration: long acting (24 hrs), once daily

  Routes: inhaled (dry powder / mist)

  Uses:

  • stable COPD, symptoms despite SABA
  • asthma if not improved by ICS/LABA

  
• What are the properties of Ipratropium (Atrovent)?

  EMERGENCY MEDICINE

  short acting antimuscarinic agent

  bronchodilation

  onset 30 mins, lasts 6 hrs

  nebulised

  acute presentations of COPD and asthma

  
• What are the properties of Theophylline?

  WHEN IV EMERGENCY MEDICINE

  Mechanism: phosphopdiesterase inhibitor, adenosine antagonist, HDCAC inhibitor

  Routes: oral (theophylline) / IV (aminophylline)

  required monitoring of level via blood test

  uses:

  • Oral: COPD & asthma (persistent)
  • IV: COPD & asthma in EMERGENCIES

  
• What are the possible adverse events of bronchodilators?

  tachycardia, angina

  nervousness, irritability, tremor

  less common when inhaled

  oral and IV more common side effects

  dose-related
• What is the systemic glucocorticoid drug with oral administration?

  prednisolone
• What is the systemic glucocorticoid drug with IV administration?

  Hydrocortisone
• What are the properties of systemic glucocorticoids?

  action unaffected by inspiratory effect / inhaler technique

  stronger effects as higher doses

  more side effects, esp with long term therapy
• What are the properties of inhaled glucocorticoids?

  localised action

  fewer side effects

  disease may prevent penetration of drug to affected areas
• What is the inhaled glucocorticoid drug?

  Beclometasone
• What are the airway effects of glucocorticoids?

  decrease:

  • release of inflammatory mediator
  • infiltration and action of WBCs
  • airway oedema
  • airway mucus production

  Increase:

  • number and sensitivity of beta-2 receptors
• What are the adverse events of glucocorticoids?

  inhaled - gargle and use spacer:

  • oral candidiasis (white plaques in mouth)
  • dysphonia (abnormal voice)

  General:

  • adrenal suppression
  • bone loss
  • slow growth in children (not ultimate height)
  • increase risk of cataracts and glaucoma
  • increase risk of gastric ulcers
  • hypertension
  • diabetes
  • mood disturbance
• What are the different combination of inhalers?

  • ICS (inhaled corticosteroids) / LABA (long-acting beta-agonists)
  • LAMA (long-acting muscarinic antagonists)/ LABA
  • ICS / LAMA / LABA
• What is the medication for allergic rhinitis?

  intranasal glucocorticoid: Beclometasone
• What are the properties of antihistamines?

  for allergic rhinitis

  H1 antagonists

  side effects: drowsiness, dry mouth, dry eyes, confusion
• What are the properties of oxygen as a drug?

  must be prescribed

  side effects: XS life threatening

  Delivery:

  • Controlled: Venturi mask
  • Uncontrolled: nasal, Hudson mask, reservoir mask

  emergency medicine
• What are the antibiotics used to treat respiratory infection?

  Penicillins:

  • Amoxicillin
  • Co-amoxiclav

  Macrolides: Clarithromycin

  Tetracyclines: Doxycycline

  (Fluoro)Quinolones: Ciprofloxacin
• What are the properties of Amoxicillin?

  MOA: inhibits bacterial cell wall formation

  moderate-spectrum, bacteriolytic, beta-lactam antibiotic

  Routes: IV/Oral

  Use: CAP (community-acquired pneumonia) / COPD / bronchitis

  Active against: Gram negative AND Gram positive bacteria
• What are the properties of Co-amoxiclav?

  amoxicillin combined with clavulinic acid (beta-lactamase inhibitor)

  to prevent degradation
• What are the properties of Clarithromycin?

  commonly used in respiratory infections (incl atypical pneumonia)

  MoA: protein synthesis inhibitor

  Route: IV/oral

  Gram positive (limited action against Gram negative)

  Side effects: GI/allergy/liver abnormality

  Interactions: anti-arrythmia drugs
• What are the properties of Doxycyline?

  MoA: inhibit bacterial protein synthesis

  Broad spectrum of action Gram positive and negative

  ORAL ONLY

  Useful for atypical infections (parasitic)

  Side effects: GI upset / staining teeth / allergy / photosensitivity

  Cautions: children <12 yo, pregnant and breastfeeding women

  Interact with food, dairy products, antacids
• What are the properties of Ciprofloxacin?

  MoA: inhibits enzymes controlling bacterial DNA replication

  Active against Gram negative and positive

  Route: Oral / IV / Inhaled

  Side effects: GI upset / precipitation of C. difficile / tendonitis

  Reserved use: to minimise Fluoroquinolone-resistance development