respiratory pharmacology Flashcards
how can drugs be grouped to treat respiratory system issues
Upper airways Allergy Lower airways Asthma COPD Respiratory infection (bronchitis, pneumonia, atypical) Interstitial lung disease Ventilatory failure
what are types of airway drugs
bronchodilators and anti-inflammatory
what are bronchodilators
Adrenergic agonists (beta 2 agonists like salbutamol, salmeterol, formoterol)
Muscarinic antagonists/anticholinergics (tioropium – long acting anti muscarinic LAMA)
Other LAMA’s include aclidinium, glycopyrronium, umeclidinium
Ipratropium short acting anti muscarinic SAMA
Methylxanthines(aminophyllines)
what are anti-inflammatory drugs
Steroids (prednisolone – oral, beclomethasone – ICS)
Leukotriene receptor antagonists (montelukast)
how are pMDIs used
deep exhale/inhale and puff/hold breath for slow ten count/exhale slowly/wait a min for second puff
use spacer/aerochamber
how are DPIs used
usually one inhalation, not puff
what is salbutamol
short acting (immediate, 3-5 hour)
inhaled/nebuliser (high dose), intravenous (rarely used)
binds to beta 2 receptors in lungs, relaxation of bronchial smooth muscles. Increase cAMP production by activating adenylate cyclase (mediate salbutamol’s actions)
SABA
Asthma and COPD
Another SABA- terbutaline
what is salmeterol
long acting (begin 2-30 min, lasts 10-12 hours)
inhaled
LABA
asthma (patients requiring long term regular bronchodilator therapy on ICS)
Always used with ICS in asthma
COPD – persistent symptoms despite SABA (LABA/LAMA combo or ICS/LABA combo FEV1 <50%)
what is formoterol
LABA but onset similar to salbutamol with prolonged duration 10-12 hours)
Inhaled LABA used for Asthma and COPD, combined with ICS for asthma
what is tiotropium
long acting 24 hours, once daily inhaled (dry powder or mist Respimat) LAMA, similar affinity for muscarinic receptor subtypes M1-5. In airways it inhibits M3 receptors at smooth muscle – bronchodilation stable COPD (symptoms despite SABA, any severity and with LABA) or asthma (not improving despite ICS/LABA – specialist advice from hospital)
what ipratropium
Short acting antimuscarinic agent
Onset 30 mins, lasts 6 hours
Nebulised
Nebulised for any acute presentations of COPD and sometimes asthma
what is theophylline
half life around 5 hours healthy adults
oral/IV
phosphodiesterase inhibitor, requires monitoring of level (blood test)
Oral – COPD and asthma – persistent symptoms
IV – COPD and asthma MEs
what adverse events arise due to brochodilators
Tachycardia Nervous, irritability, tremor Inhaled preparations – less common Oral preparations (hardly used) and IV – more SE common (tachyarrhythmias and angina) Usually dose regulated
what are the systemic effects of glucocorticoids
Systemic (eg Prednisolone)
IV or oral
Stronger effects as higher doses
Action unaffected by insp effort/inhaler technique
More SEs, esp long term therapy
Inhaled (eg beclomethasone, fluticasone, budesonide)
what are the localised effects of glucocorticoids
Fewer SE, some absorption occurs
Disease may prevent penetration of drug to affected areas
what are the airway effects of glucocorticoids
Decrease release of inflammatory mediator
Decrease filtration and action of WBCs
Decrease airway oedema
Decrease airway mucus production
Increase number and sensitivity of B2 receptors
what adverse events result from glucocorticoids when inhaled
Inhaled – gargle and use spacer Oral candidiasis (white plaques) and dysphonia
what adverse events result from glucocorticoids
General Adrenal suppression Bone loss – exercise, vit D, calcium Slow growth in children but not ultimate height Increase risk of cataracts and glaucoma Increased risk of infection Gastric ulceration Hypertension Diabetes Mood disturbance
what are combination inhalers
ICS/LABA (formoterol/budesonide, formoterol/beclomethasone, salmeterol/fluticasone)
LAMA/LABA (eg tiotropium/olodaterol)
ICS/LABA/LAMA (beclomethasone/formoterol/glycopyrronium)
what is the asthma treatment ladder
Steps, move up ladder depending on symptoms and success of current drugs Side effects (important to move down as well as up, patients often left on too much steroid)
how can allergic rhinitis be treated
Antihistamines Cetirizine, chlorpheniramine H1 antagonists Intranasal glucocorticoids Montelukast (Singulair) Sympathomimetics (decongestants) – alpha agonists, issues with abuse and MAOI
what are side effects of antihistamines
Side effects – drowsiness, dry mouth, dry eyes, confusion
what does montelukast do
inhibit leukotriene receptors, decrease inflammation, bronchoconstriction, oedema, mucus, recruitment of eosinophils
how is oxygen delivered
Controlled (venturi) or uncontrolled (nasal, Hudson, reservoir)
