Anti-Asthma drugs

Question 1

What is asthma?

Answer 1

Respiratory disorder- airways hyper responsive
Associated with airflow limitation
Bronchial inflammation

Question 2

What is an asthma attack?

Answer 2

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

Question 3

What are the symptoms of asthma?

Answer 3

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

Question 4

What triggers asthma?

Answer 4

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

Question 5

What are the long term aims of asthma therapy?

Answer 5

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

Question 6

When does an allergic asthma attack occur?

Answer 6

1. Sensitisation phase: 1st exposure to allergen. Activates the T cells
2. Inflammatory mediators are secreted called interleukins and activate the B cells.
3. B cells become plasma cells and secrete antibodies known as IgEs
4. These bind to mast cells
5. When re exposed to allergens, the allergen binds to the IgEs on the surface of mast cells, results in histamine release
6. Re exposure prompts early face reaction immediately
7. Late phase reaction: 3-10 hours
8. Eosinophils can be very damaging to the lining of the airways.

Question 7

What are bronchodilators?

Answer 7

They are relievers, relax the smooth muscles.

Question 8

What is Salbutamol?

Answer 8

The most common from of bronchodilator (ventolin)

Question 9

Which bronchodilator is longer lasting?

Answer 9

Salmeterol

Question 10

For severe asthma, which drug is used?

Answer 10

Theophylline

Question 11

Which bronchodilator blocks mucus secretion?

Answer 11

Ipratropium

Question 12

What are the two categories of anti asthma drugs?

Answer 12

1. Relieve symptoms

2. Stop symptoms occurring- take regularly

Question 13

What does B2 adrenoceptor agonist do?

Answer 13

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

Question 14

What are preventers?

Answer 14

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

Question 15

What is glucocorticosteoids?

Answer 15

It is a prophylactic, may be taken orally, inhaled or IV.

Question 16

Which receptor in the SNS is a target for drugs?

Answer 16

A1= blood vessels
A2= VMC
B1= Heart
B2= Lungs, blood vessels, muscle spindles (targets for anti asthma drugs)

Question 17

What does salbutamol do?

Answer 17

Similar structure to adrenaline
Selective to B2 receptors on the SNS
Widen the airways, smooth muscles relax

Question 18

Explain the B2 agonists

Answer 18

Short acting drugs: Salabutimol, Terbutaline
Longer acting drugs: Salmeterol, formoterol

Inhaler or tablets

Question 19

What are the side effects of B2 agonists?

Answer 19

Resting tremor
Increased heart rate
Decreased potassium
Nervous tension headache

Question 20

What is a MDI?

Answer 20

Metered dose inhaler, contains a bronchodilator drug.

Breath-activated inhaler.

Question 21

Why is inhalers not very efficient?

Answer 21

Following the correct use of MDI:
50% impacts on mouth
10% reaches the lungs
90% swallowed
-depends on pt technique

Question 22

What is an accuhaler?

Answer 22

Dry powder inhaler, activated by moving a lever on the side

• sharp intake of breath is sufficient to take in the drug
• device has a counter, let’s you know how much drug remains

Question 23

What is the turbohaler?

Answer 23

Dry powder inhaler, can deliver 100 consecutive doses. Next dose ready when base moves back and forth.

• contains 200 doses
• desiccant keeps powder dry by absorbing moisture
• does not contain lactose, no taste when does administered

Question 24

Describe the use of nebuliser in children.

Answer 24

Small plastic container filled withdraw solution
Compressor blows air/oxygen through the solution, makes aerosol/mist
Mist breathed in via mask or mouth piece
Severe asthma attack at GP or A/E department

Question 25

What anti-asthma drugs are used as preventers?

Answer 25

Glucocorticosteoids via inhaler Beclometasone is the most prescribed medicine, not aimed for rapid relief but helps control symptoms when taken routinely, oral inhalant or nasal spray Budesonide-relief within 10'hours, Fluticasone, Mometasone Relief- 3-7days, bioavailability poor, systemic side effects minimal

Question 26

What are combination inhalers?

Answer 26

Beta 2 agonist and steroids 1. Symbicort- budesonide/ formoterol 2. SMART- Symbicort Maintenace And Reliever Therapy 3. Fluticasone Salmerterol

Question 27

What is the benefit of a combined inhaler?

Answer 27

Carry less inhaler with you.

Question 28

What is the mechanism of action for glucocorticosteoids?

Answer 28

Synthesised from cholesterol= highly lipidphillic, can cross cell membrane Once inside, bind to steroid receptor Drug-receptor complex allows the drug to migrate across to the nucleus Brings to DNS, induces or suppresses specific genes- protein production i.e. GC inhibit transcription of cox 2 gene, resulting in reduced protein production, reduced inflammation

Question 29

What are the side effects of glucocorticosteoids?

Answer 29

``` Candida Albicans (oral thrush) Dysphonia (hoarseness) ``` Can be reduced by rinsing month/ gargling or using a spacer

Question 30

When is oral prednisolone used?

Answer 30

Treatment for acute asthma attack 7 days of high doses In chronic asthma- combine with high does of inhaled steroids

Question 31

What is the mechanism of action for oral prednisolone?

Answer 31

Suppresses the activity of the immune system and the release of inflammatory mediators, rapidly reduce symptoms.

Question 32

What are the side effects of oral corticosteroids?

Answer 32

Buffalo hump- crushing syndrome Increased abdominal fat- redistribution of fat Crushing features- growth- children Osteoporosis - decrease calcium absorption, increased calcium excretion via kidneys Thinning of skin Poor wound healing- inflammation has a key role in wound healing Muscle wasting- protein breakdown Hypertension Moon face Hyperglycaemia- increase and decrees of glucose production

Question 33

What are the dangers of stopping steroid treatment abruptly?

Answer 33

Sudden withdrawal can result in acute adrenal insufficiency, pts ability to synthesise corticosteroids is suppressed Unable to respond to stress from illness or trauma Result: Addison crisis- pts have symptoms of shock. Can die in untreated.

Question 34

What are anti-muscarininc brionchodilators?

Answer 34

Short acting relievers Severe asthma: used alongside high doses inhaled corticosteroids Block Muscarinic receptors, inhibiting bronchoconstriction I.e. Ipratropium

Question 35

What is the mechanism of actions for M antagonist?

Answer 35

Slower to act than beta agonist, block the construction caused by activation of the PNS Because IPratropium blocks R receptors Side effect: dry mouth (SNS), precipitate glaucoma

Question 36

What are cromones?

Answer 36

Inhibits the release of chemicals from inflammatory cells called mast cells- prevents bronchospasm Reduces allergen induced response and bronchospasm Cromones stop the mast cells from releasing histamine to prevent symptoms occurring

Question 37

What are leukotriene receptors antagonists?

Answer 37

Leukotriene receptor causes bronchoconstriction, release of inflammatory cells and increase section in the airways Relax and prevent inflammation May cause GI DISTURBANCE. Exeter induces asthma

Question 38

Examples of leukotriene receptor antagonist

Answer 38

Montelukast | Zafirlukast

Question 39

What is theophylline?

Answer 39

Oral/IV persistent symptoms/ severe acute asthma Use withB agonist and or steroids Blocks PDE enzyme in airways, causing muscle to relax Anti-inflammatory effect

Question 40

Side effects of theophylline?

Answer 40

Tachycardia Palpitations Headaches Convulsions

Question 41

What is the mechanism of action op for theophylline?

Answer 41

Blocks PDE enzyme, which breaks down cAMP into 5'AMP. So more cAMP is available to stimulate smooth muscle relaxation

Question 42

What is Omalizumab?

Answer 42

Expensive drug Antibody given SC, EVERY 2-4 weeks Adults with severe allergic asthma not controlled with b agonist or steroids Antibody that stops the IgE binding to receptors on the surface of mast cells and basophils Prevents the release of pro- inflammatory mediators and reduces allergen-induced airways reaction

Question 43

Side effects of Omalizumab?

Answer 43

Bruising Pain Small risk of anaphylaxis

Question 44

What is the treatment strategy for asthma?

Answer 44

Mild to severe 1. Inhaled shirt acting B 2 agonists (as needed) or inhaled Ipratropium or oral b agonist or theophylline 2. Inhaled steroids 3. Inhaled long acting b2 agonists with increased dose of inhaled steroids 4. Short and long acting b2 agonist and inhaled steroids and and another drug such as Leukotriene receptor antagonist 5. Continuation or frequent use of oral steroids and immunosuppressants

Question 45

When should prophylactic treatment be considered?

Answer 45

If b2 agonist inhalation is needed more often than twice a week If symptoms disturb sleep more than once a week If the patient has suffered an exacerbation in the last 2 years

Question 46

What is the therapy for acute asthma attack?

Answer 46

1. Bronchodilators given via nebuliser 2. Corticosteroids- route depends on severity, oral prednisolone or IV hydrocortisone 3. Oxygen therapy needed if oxygen saturation of blood reduces are less than 93% 4. If poor response then administer aminophylline injection for severe and acute attack 5. Nebuliser enable deeper penetration into bronchial tree

Question 47

What are the two main prescribed anti-asthma drugs?

Answer 47

Relievers: b agonist Preventers: steroids