Asthma and COPD

Question 1

Describe the stages of an asthma attack?

Answer 1

Early phase, spasmonogens lead to bronchospasm and symptoms of an acute asthma attach, SOB & wheeze.

Later phase: leukotrienes attract eosinophils and mononuclear cells leading to inflammation + airway hyper-reactivity.

Question 2

Describe the autonomic control of the bronchi?

Answer 2

Sympathetic: (running from a tiger, you need air)
B2 receptors stimulate bronchodilatation.

Parasympathetic:
ACh binds to muscarinic receptors stimulating bronchoconstriction.

Question 3

Describe the pharmacological basis of therapy in asthma?

Answer 3

Relievers:
To relieve acute exaserbations e.g beta agonists (salbutamol aka ventolin blue inhaler)

Preventers:
To prevent attacks and reduce chronic inflammation.

Question 4

Describe the stepped pharmaceutical approach to treating asthma?

Answer 4

Step 1: SABA (short acting beta agonist)

Step 2: SABA + inhaled corticosteroid

Step 3: Step 2 + trial LABA (long acting beta agonist) if not effective try xanthines or a Leukotriene receptor antagonists (LTRAs)

Step 4: Increase inhaled corticosteroid dose

Step 5: Start oral steroids

Question 5

Give examples and describe the mechanism of actions of SABA’s (short acting beta agonist) and LABA’s?

Answer 5

Are agonists to the B2 receptors on the bronchi and cause bronchodilatation. (increase cAMP)

SABA’s: are reliever inhalers such as salbutamol

LABA’s: are long acting and therefore don’t provide immediate relief but are used as relievers e.g salmeterol

Question 6

Describe what sort of drug xanthine is, important prescribing points and give examples?

Answer 6

They are bronchodilators. They act by inhibiting phosphodiesterase which breaks down cAMP, there is therefore more cAMP and more bronchodilatation.

Oral = theophylline 
IV = aminophylline (emergencys)

Note has a narrow TI, many drug interactions and may cause hypokalaemia particularly if used with B2 agonists.

Question 7

Describe the mechanism of action of leukotriene receptor antagonists?

Answer 7

They antagonise leukotrienes and therefore cause bronchodilatation and reduce inflammation.

Question 8

Describe how glucocorticoid steroids are helpful in asthma and their mechanism of action?

Answer 8

Preventative:
Anti-inflammatory by activation of intracellular receptors, leading to altered gene transcription (decrease cytokine production) and production of lipocortin

Lipocortin inteferes with arachidonic acid production which is involved in the production of prostoglandins and leukotrienes.

Net result reduces leukotrienes and prostoglandins.

Note: mineralocorticoids have aldosterone like affects: Na+ and H2O retention and K+ loss.

Question 9

Give some examples of inhaled and oral steroids and describe some of the common side effects?

Answer 9

Inhaled: beclometasone.
S/e: local immunosuprression aka throat infections such as oral thrush. Hoarsening of the voice laryngeal myopathy.

Oral: Prednisolone
S/e: Immunosupression, central obesity, thinning of the skin, osteoporosis, diabetogenic, cushingoid, adrenal suppression.

Question 10

Describe the classification of COPD?

Answer 10

Mild: FEV 1 80-60%
Moderate: FEV1 59-40%
Severe: FEV1

Question 11

What important drug advice should you give asthmatics?

Answer 11

Never take a beta blocker.

Don’t take NSAIDs can worsen asthma as leads to increased leukotriene production (in place of prostoglandins)

Question 12

Describe how you would manage COPD, lifestyle and pharamceutically?

Answer 12

Smoking cessation

Step 1 Salbutamol or short acting anti muscarinic

Step 2
If FEV1 > 50%: Replace the short acting medication from step1 with a LABA
If FEV1