Anti-Asthma drugs Flashcards
What is asthma?
Respiratory disorder- airways hyper responsive
Associated with airflow limitation
Bronchial inflammation
What is an asthma attack?
Construction of the airways caused by smooth muscle contraction, swelling, inflammation, excessive production of mucus.
Limiting the flow of air through the narrow bronchioles, wheezing on expiration.
Traps air in lungs, reducing efficiency of gas exchange
What are the symptoms of asthma?
Related to the narrowing of the airways.
Cough caused by irritation and attempt to clear airways
Symptoms are worse at night
Wheezing attacks
Shortness of breath
Cough
What triggers asthma?
Dust mites Exposure to allergens Cold, dry air- increases concentration of the fluid king the bronchi, causing histamine and leukotrienes to be released from mast cells. Cigarette smoke Excitement, stress, anger Drugs- aspirin, beta blockers
What are the long term aims of asthma therapy?
Abolish symptoms Maintain optimal lung function Prevent permanent lung damage Avoid unnecessary side effects Allow patent to remain symptom free for as long as they can
When does an allergic asthma attack occur?
- Sensitisation phase: 1st exposure to allergen. Activates the T cells
- Inflammatory mediators are secreted called interleukins and activate the B cells.
- B cells become plasma cells and secrete antibodies known as IgEs
- These bind to mast cells
- When re exposed to allergens, the allergen binds to the IgEs on the surface of mast cells, results in histamine release
- Re exposure prompts early face reaction immediately
- Late phase reaction: 3-10 hours
- Eosinophils can be very damaging to the lining of the airways.
What are bronchodilators?
They are relievers, relax the smooth muscles.
What is Salbutamol?
The most common from of bronchodilator (ventolin)
Which bronchodilator is longer lasting?
Salmeterol
For severe asthma, which drug is used?
Theophylline
Which bronchodilator blocks mucus secretion?
Ipratropium
What are the two categories of anti asthma drugs?
- Relieve symptoms
2. Stop symptoms occurring- take regularly
What does B2 adrenoceptor agonist do?
Relievers: Salbutamol, muscadine receptor antagonist, which reverse the bronchial constriction caused by parasympathetic stimulation and inhibit the rise in mucks secretion.
Can be used in addition to b agonist drugs: alkylanthines I.e. Theophylline
What are preventers?
Anti inflammatory, stop response of allergen.
Preventers-prophylactics- do not have bronchodilator activity. Work by reciting immediate and late phase asthmatic response. Reduce bronchial activity
Beclometasone
Sodium cromaglicate (steroid drugs)
Montelukast
What is glucocorticosteoids?
It is a prophylactic, may be taken orally, inhaled or IV.
Which receptor in the SNS is a target for drugs?
A1= blood vessels A2= VMC B1= Heart B2= Lungs, blood vessels, muscle spindles (targets for anti asthma drugs)
What does salbutamol do?
Similar structure to adrenaline
Selective to B2 receptors on the SNS
Widen the airways, smooth muscles relax
Explain the B2 agonists
Short acting drugs: Salabutimol, Terbutaline
Longer acting drugs: Salmeterol, formoterol
Inhaler or tablets