18 Respiratory Pharmacology Flashcards
What is ‘uncontrolled asthma’ defined as?
asthma that has an impact on a person’s lifestyle or restricts their normal activities
Guidelines:
- 3+ days with symptoms eg coughing, wheezing, shortness of breath, chest tightness
- 3+ days needing to use SABA for symptomatic relief
- 1+ nights per week awakening due to asthma
What 3 factors should we consider before stepping up or stepping down asthma management?
- Adherence
- Inhaler technique
- Eliminate trigger factors
Name 3 inhaled corticosteroids.
- Beclometasone
- Budesonide
- Fluticasone
How do inhaled corticosteroids work to treat asthma?
When are they indicated?
What is their action?
What is their mechanism of action?
Indicated:
- Regular preventer when reliever alone no sufficient
- Reduce symptoms, exarcerbations and death
Action:
- Reduce mucosal inflammation
- Widen airways
- Reduce mucous
Mechanism of action:
- Activate cytoplasmic receptors
- Activated receptor passes into nucleus to modify transcription
What are some of the side effects/complications of the immunosupressive actions of inhaled corticosteroids?
- Candiasis
- Hoarse voice
- Pneumonia risk with COPD
(if taken correctly- few significant ADRs)
Why do corticosteroid need to be inhaled?
Almost complete first pass metabolism
Poor oral bioavailability
Direct to site of action
- High affinity for glucocorticoid receptor
- Slow dissolution in aqueous bronchial fluid
Beta agonists are used in the treatment of asthma. What are the indications for SABAs and LABAs?
SABAs= symptom relief through bronchodilation
LABAs= add on therapy to ICS and SABA
Both-
aim to prevent bronchoconstriction prior to exercise
increase mucus clearance by action of cilia
Why should SABAs be taken for asthma only when needed?
Can acquire tolerance to SABAs if taken inappropriately
Give some examples of SABAs and LABAs.
What are some of the side effects of Beta 2 agonists?
Adrenergic- fight or flight effects:
- Palpitations
- Tachycardia
- Anxiety
- Tremor
- SVT
LABA- muscle cramps
REMEMBER- beta blocker- may reduce actions so just be aware of interaction
Why should a LABA not be used on its own and what should it be given with?
LABA- should be given with ICS
Increased risk of death when prescribed alone
Alone can mask airway inflammation and near fatal attacks
When is a LABA added to the management of asthma?
- When asthma not controlled with ICS
- To improve lung function
- Reduce asthma exacerbations
How do the LABAs formoterol and salmeterol compare?
Formoterol= more potent and more efficacious than salmeterol
Give an example of a leukotriene receptor antagonist. (LTRA)
Montelukast
What are the indications for Montelukast (LTRA)?
= alternative to LABA in NICE guidlines
How do LTRAs eg Montelukast work to treat asthma?
(Leukotriene receptor antagonist)
Leukotrienes cause:
- bronchoconstriction
- increas mucus
- increase oedema
through CysLT1- GPCR
LTRA block CysLT1
Give some ADRs for LTRAs. (eg montelukast)
- Headache
- GI disturbance
- Dry mouth
- Hyperactivity
What can be given to asthmatics as last step therapies? (3)
Give examples of each.
LAMA (long acting muscarinic antagonist) (M3)
Severe asthma and COPD
- Tiotropium
Methylxanthine
- Theophylline
Oral steroids
Severe uncontrolled asthma
Post acute exacerbation- at least 5 days
Post COPD acute exacerbation- 5-7 days
- Prednisolone
List the main ADRs for LAMAs eg tiotropium.
- Dry mouth
- Urinary retention
- Dry eyes
(typical anticholinergic effects)
Why does caution need to be taken when prescribing theophyline?
Narrow therapeutic index
Potentially life threatening complications including arrhythmia
Need to consider interactions with CYP450 inhibitors
How do methylxanthines work?
Adenosine receptor antagonist
How should we manage acute severe and life-threatening asthma?
- Oxygen
- Beta 2 agonist
- High dose
- Nebulised
- Oxygen driven
- SAMA (if needed with Beta agonist)
1. eg Ipratropium
- SAMA (if needed with Beta agonist)
- consider i.v theophylline
- Oral steroids
- 7-14 days
- Continue ICS alongside
What are the 5 tasks involved in COPD management?
- Confirm diagnosis
- Stop smoking
- MRC Dyspnoea scale + Offer pulmonary rehabilitation
- Vaccinations
- Flu
- Pneumococcal
- Consider medication
What drugs might we need to give someone who has had an acute exacerbation of COPD requiring hospitalisation?
- Salbutamol (nebulised, driven by air not o2)
- +/- ipratropium (SAMA)
- Oral steroids (may be more effective in asthma)
- Antibiotics
Give 3 inhaler types that you can get (in terms of use).
- Pressurised metered dose inhalers (pMDI)
- Inhalation and actuation of device (slow breath and hold) can be used with spacer
- Breath-actuated (automatic)
- Dry powder inhalers (DPI)
- Fast deep inhalation
Why is inhaler technique so important?
Dictates particle size and depostion
Can use In-check DIAL device as guide for technique
For future reference- Respiratory inhalers
