PHARMACOLOGY: Respiratory Drugs Flashcards
List the 6 aspects of treatment of asthma.
- High flow oxygen
- Nebulised bronchodilators
- IV magnesium
- IV salbutamol/aminphylline
- Steroids
- Possible ventilation
List the 6 aspects of COPD treatment.
What is the most important difference between this and asthma therapy?
- Controlled oxygen (NOTE: never high flow in case they’re in type 2 resp failure)
- Nebulised bronchodilators
- IV salbutamol/aminophylline
- Mucolytics
- Steroids
- Consider ventilation
Give 2 examples of steroids used in asthma/COPD.
Beclomethasone
Prednisolone
List the 3 classes of bronchodilators.
Beta 2 agonists
Anti-muscarinic bronchodilators
Theophylline
Give 3 examples of beta 2 agonists.
Are they long or short acting?
SHORT ACTING:
Salbutamol
LONG ACTING:
Salmoterol
Formoterol
Give 2 examples of anti-muscarinic bronchodilators.
Are they long or short acting?
SHORT ACTING:
Ipratropium bromide
LONG ACTING:
Tiotropium
What other type of drug might be used in asthma?
Give 2 examples.
Leukotriene receptor inhibitors
Examples:
Montelukast
Zafirlukast
What other type of drug might be used in COPD?
Give 1 example.
Mucolytic drugs
Example:
Carbocysteine
List 3 antibiotics commonly used in the respiratory system.
Amoxacillin
Clarithromycin
Doxycycline
Co-trimoxazole
Give 2 examples of inhalers which combine steroids with long acting beta 2 agonists.
State which drugs are in them.
Seretide - fluticasone PLUS salmeterol
Symbicort - budesonide PLUS formoterol
Describe the mechanism of steroids in COPD/asthma. (3)
- Anti-inflammatory effect, causing decreased cell recruitment, e.g. of
- T lymphocytes
- Macrophages
- Eosinophils - Acts as a transcription factor, causing decreased cytokine production
- Causes upregulation of beta 2 adrenoreceptors
- This causes increased responsiveness to beta 2 agonists
List 3 adverse effects of steroids.
Oral candidiasis
Adrenal suppression
Osteoporosis
What would you tell patients when you prescribe them inhaled steroids? (2)
If on high doses, they should carry a steroid card
Increased dose during periods of illness
Describe the mechanism of action of salbutamol.
NOTE: other beta 2 agonists work in exactly the same way, even if they’re long acting.
- Short acting beta 2 agonist (SABA)
- Causes relaxation of bronchial smooth muscle
- This causes bronchodilation - Inhibits cytokine release from mast cells and TNF alpha from monocytes
- This reduces airway inflammation - Increases mucous clearance from airways by stimulating cilia action
List 6 side effects of salbutamol.
Tremor Tachycardia Arrhythmias Headache Sleep disturbances Flushing
List 3 side effects of high dose salbutamol.
Hypokalaemia
Hyperglycaemia
Hypomagnesaemia
What would you tell the patient when prescribing salbutamol? (2)
Check inhaler technique
If blue inhaler is needed more than once daily, then you need to review treatment
What would you tell the patient when prescribing salmeterol? (3)
Report any deterioration in symptoms
Do not exceed stated dose
Seek medical advice when stated dose fails to control symptoms
Describe the mechanism of action of anti-muscarinic bronchodilators. (3)
- Muscarinic receptor (M3) antagonists
a. Normally, parasympathetic cholinergic/M2/M3 receptors cause bronchoconstriction
b. When inhibited, there is bronchodilation - Reduces mucous secretion
- May increase mucous clearance by stimulating cilia action
List the side effects of anti-muscarinic bronchodilators. Consider:
a) Ipratropium bromide (3)
b) Tiotropium bromide (2)
IPRATROPIUM:
Blurred vision
Dry mouth
Decreased gut motility
TIOPTROPIUM:
Dry mouth
Dysuria
How should nebulised ipratropium bromide be administered?
Why?
Via mouthpiece
Minimises risk of acute angle closure glaucoma (sudden, severe eye pain and reduced vision)
Describe the mechanism of action of theophylline. (2)
- Inhibits phosphodiesterase type 4 enzyme (PDE4)
a. This causes bronchodilation - Increases mucous clearance by stimulating cilia action
List 3 side effects of theophylline.
What are the features of serious drug theophylline? (4)
GI irritation
Tachycardia
CNS stimulation
Severe toxicity:
- Hypokalaemia
- Ventricular tachycardia
- Ventricular fibrillation
- Seizures
Which drugs will theophylline have drug interactions with?
CYP450 inducers/inhibitors
theophylline is metabolised by CYP450
Describe the mechanism of action of leukotriene receptor inhibitors. (2)
- Block cysteinyl leukotriene receptor (CysLT1) in smooth muscle/macrophages
- Inhibit eicosonoids LTC4, LTD4 and LTE4 release from mast cells/eosinophils
Describe the mechanism of action of mucolytic drugs. (2)
- Facilitate expectoration by decreasing sputum viscosity
2. May reduce exacerbations of COPD in some patients
What is the main difference between type 1 and type 2 respiratory failure?
What causes the respiratory drive in each?
TYPE 1:
Low/normal pCO2
Low pO2
Respiratory drive: high pCO2
TYPE 2:
High pCO2
Low pO2
Respiratory drive: low pCO2 (because body is used to high pCO2)
