Flashcards in Pharmacotherapy of airflow obstruction Deck (88)
What 2 categories can drugs for airflow obstruction be divided into?
* Preventers (anti-inflammatory)
* Relievers (bronchodilators)
Describe an asthmatic inflammatory response to an allergen
* Allergen digested into TSLP
* TSLP digested and presented by dendritic cells
* Dendritic cell travels to lymph node and presents antigen to CD4+ T cell via MHC II complex
* Proliferate to form TH0 cells
* TH0 cell proliferates to form TH2 cell
* TH2 cell releases IL-4, which stimulates expansion of B cell population
* TH2 also releases IL-5 which recruits eosinophils
* B cells proliferate to form plasma cells, which secrete IgE
* IgE binds to IgE receptors on mast cells, activating them
What do eosinophils do?
* Basic and cationic proteins
What causes hyper-secretion of mucous in asthma?
Leukotriene D4 acting on goblet cells
What cell releases Leukotriene D4?
When are monoclonal antibodies used to treat asthma?
When inhaled corticosteroids are ineffective in treating inflammation
What is a reliever drug for asthma?
Short-acting B2 agonist
What is the 1st line preventer for asthma?
Inhaled corticosteroids (e.g. cromoglycate)
What are examples of controllers?
(2nd line additives to ICS)
* Leukotriene receptor agonist (LTRA)
* Long-acting B2 agonist (LABA)
* Long-acting muscarinic antagonists (LAMA)
What treatment is used for the most severe cases of asthma?
What combinations of treatment are used for severe asthma?
* Inhaled corticosteroids
When is the only time LAMA and LABA can be used?
In addition inhaled corticosteroids
What is the disadvantage of using corticosteroids?
May predispose COPD sufferers to pneumonia
How do corticosteroids predispose COPD sufferers to pneumonia?
* Local immune suppression
* Impaired mucocilliary clearance
Are oral steroids (e.g. prednisolone) used for maintenance of asthma?
No, only used for acute exacerbations
Why is prednisolone (oral steroid) only used for acute exacerbations and not maintenance therapy?
It has a very low therapeutic ratio
What is an example of an oral steroid used in asthma?
What is an example of an inhaled corticosteroid?
Why are inhaled steroids used for maintenance monotherapy in asthma?
They have a high therapeutic ratio
When is the only time inhaled corticosteroids are effective in treating asthma?
In combination with LABA
(not as monotherapy)
What effect does an ICS/LABA combo have on COPD in ACOS?
If COPD sufferer has eosinophilia (>4%), reduces exacerbations in eosinophilic COPD (aka ACOS)
What is used to optimise lung delivery of inhaled corticosteroids?
Extra fine solution HFA/spacer
Why are doses of inhaled corticosteroids kept low in patients with ACOS?
Want to remove eosinophils but do not want to cause pneumonia
What is the safest inhaled corticosteroid to use in COPD?
Why are inhaled corticosteroids not effective in non-eosinophilic COPD?
Cannot melt away neutrophils
What are the most dangerous steroids for COPD?
* Fluticosone proprionate
* Flucticosone furoate
Why are fluticosone proprionate and flucticosone furoate the most dangerous steroids for COPD?
Stay in the lungs for a long time causing immuno-suppression (greater risk for pneumonia)
Why do inhaled corticosteroids have a large therapeutic ratio?
Directly delivered to site of tissue action (lungs) – do not require large doses
What is eosinophilia?
>4% eosinophils in the blood