Lecture 17 - Respiratory Drugs Flashcards
What is asthma?
Chronic inflammatory airway disease with intermittent airway obstruction and hyper-reactivity small airways
Its is reversible broth spontaneously and with drugs
What is considered controlled asthma?
Minimal symptoms during day and night
Minimal need for reliever
No limitation of physical activity
Normal lung function
What is uncontrolled asthma?
The asthma has an impact on a perosns lifestyle restricting their normal activities
Before stepping up treatment for asthma, what must be done?
Ensures correct inhaler technique
Ensure adhering to treatment
Remove triggers
What is the initial add on therapy if a person has uncontrolled asthma?
According to BTS guidelines
Give Long Acting Beta Agonist (with their inhaled corticosteroids)
What is the initial add on therapy for a person with uncontrolled asthma according to NICE guidelines?
Add Leukotriene Receptor Antagoinst instead of LABA (with their Inhaled corticosteroids)
What are some examples of inhaled corticosteroids?
Beclometasone
Budesonide
Fluticasone
What is the general way that inhaled corticosteroids work?
Pass through plasma membrane, activate cytoplasmic receptors, activated receptor then passes into neucleus to modify transcription
What do inhaled corticosteroids do?
Reduces mucosal inflammation
Widens airways
Reduces mucus
Reduces symptoms, exacerbations preventing death
What are the adverse drug reactions of inhaled corticosteroids?
Local immunosuppressive action (candidiasis and hoarse voice)
What are the contraindications for inhaled corticosteroids?
Pneumonia risk possible in COPD at high doses
What are the ADRs for inhaled corticosteroids?
Very few if taken correctly q
What is the mechanism of action of steroids?
Go into the nucleus increasing nuclear transcription increasing B2 receptors and anti-inflammatories
Why is a poor oral biboavialibaltu for inhaled corticosteroids an advantage?
Means unlikely to have systemic side effects
What type of eof receptor do inhaled corticosteroids have a high affinity for?
Glucocorticoid receptor
What is a fast short acting B2 agonist?
Salbutamol
What is an example of a slow long acting B2 agonist?
Salmeterol
What do short acting B2 agonists do?
Reverse bronchoconstriction relieving symptoms (only to be used p.r.n)
What do Long Actting B2 agonists do (LABA)?
Add on therapy to inhaled corticosteroids and p.r.n SABA
Prevents bronchoconstriction before exercise and increases mucus clearance by cilia
What are the adverse effects of B2 agonists?
Adrenergic fight or flight effects
Tachycardia (palpitations), anxiety and tremor
Inc glycogenolysis and inc renin in kidney
Supraventricular tachycardia
What are the contraindications for B2 agonists?
LABA (Salmeterol) should only be taken alongside inhaled corticosteroids
LABA alone can mask airway inflammation and near fatal; and fatal attacks
The tachycardaia may provoke angina
Why are combined fixed dose inhalers with Inhaled Corticosteroids and LABA benefical?
Improves adherence
What drug must LABA (Salmeterol) always be prescribed alongside with?
Inhaled corticosteroids
What are the drug drug interactions of B2 agonists?
B blockers may reduce effects
What type of drug is montelukast?
Leukotriene receptor antagonist (LTRA)
When is montelukast (Leukotriene receptor antagonist) used?
As an alternative to LABA in the 2nd step in the NICE guidelines for asthmatics
What is the mechanism of action for montelukast (Leukotriene receptor antagonist) in asthma?
Leukotrienes are released by mast cells and eosinophils and cause:
-bronchoconstriction
-inc mucus
-oedema
By binding to CysLT1 (GPCR)
So drug blocks CysLT1 receptor at CYSLTR1
What are the adverse drug reactions for montelukast (LTRA)?
Headache, GI disturbance, dry mouth and hyperactivity
What are the contraindications and drug-drug interactions for montelukast (LTRA)?
Contra = neuropsychiatric
Drug = no major drug reactions
What are long acting muscarinic antagonists used for?
Severe asthma
COPD
What is an example of Long Acting Muscarinic Antagonist?
Tiotropium
What is the mechanism of action of Tiotropium (Long Acting Muscarinic Antagonist LAMA)?
Blocks vagally mediated contraction of airway smooth muscle
What are the adverse drug reactions for Tiotropium (LAMA)?
Infrequent anticholinergic effects (dry mouth, urinary retention dry eyes)
What is the drug Theophylline used for?
Chronic poorly controlled asthma
What is the mechanism of action of theophylline?
Antagonises adenosine receptor and inhibts phosphodiesterase (cAMP and cGMP levels rise) so more PKA so more MLCK phosphorylated so less MLC phosphylated so causes LESS BRONCHOCONSTRICTION
What are the contraindications for theophylline?
It has a narrow therapeutic index so can cause potentially life threatening complications like arrhythmias
What are the drug drug interaction for theophylline?
CYP450 inhibtors so increase concentrations of theophylline
When should asthmatic patients self management plans be reviewed?
Following treatment for an exacerbation following a hospital discharge
What may be the cause of asthma in elite athletes?
May be exercise induced bronchospasm
May be due to cold air or pollutants
What is considered acute severe?
Unable to complete sentences
Resp rate >25min
HR > 110bp/min
What is considered life-threatening asthma?
All acute severe asthma symptoms +:
Peak flow < 33%
Arterial oxygen sats < 92%
Silent chest, cyanosis, poor Resp effort, arrhythmia, exhaustion
What oxygen saturation is considered acute severe and life threatening asthma?
94% - 98%
What are some steroids used for acute severe and life-threatening asthma?
Prednisolone
Hydrocortisone
What is the method of administration for prednisolone?
Oral
What is the method of administration for prednisolone?
Oral
What is the method of administration for hydrocortisone (glucocorticoid) ?
IV
What is an example of a short acting Muscarinic antagonist (SAMA) for acute severe and life-threatening asthma?
Ipratropium (nebulised)
When is IV magnesium sulphate used?
Life threatening asthma
What is a short acting Muscarinic antagonist (SAMA)?
What is a long acting Muscarinic antagonist (LAMA)?
SAMA = ipratropium
LAMA = Tiotropium
I comes before T in the alphabet so SAMA = ipratropium
What are the 5 steps to managing COPD?
Confirm diagnosis
Smoking cessation
Breathlessness score
Vaccinations
Medication
What drugs are given in acute exacerbations of COPD?
Nebulised salbutamol
And/or
Ipratropium
If a patient with COPD acute exacerbation is hypercapnic or acidotic, what should drive the nebuliser, air or oxygen?
Nebuliser with salbutamol and ipratropium should be driven by air
Why can oral steroids be less effective than in eosinophilic asthma?
Reduced action on neutrophils in many with COPD
What are pressurised metered dose inhalers?
Have to inhale and push button (can use spacer to help)
What are dry powered inhalers?
Microionisd drug plus carrier powder
Why is technique extremely important when taking inhalers?
Drug may not end up in the lungs
