respiratory pharmacology

Question 1

bronchodilator drugs

Answer 1

B2‐adrenoceptor agonists promote muscle relaxation by stimulating AC to produce cAMP.
Muscarinic antagonists prevent ACh binding to receptors that make muscle contract.
Theophylline raises the level of cAMP by inhibiting its breakdown by PDE

Question 2

B2 agonists

Answer 2

• Relax smooth muscle by activating G protein coupled receptors, activating adenyl cyclase, which in turn increases cyclic AMP production. This causes vasodilation and inhibits the release of inflammatory mediators such as histamine and PGD2 from mast cells, It also increases K+ intake.
• Used for treatment of COPD, asthma and hyperkalaemia.
• Side effects: hypokalaemia, tachycardia, palpitations, skeletal muscle tremors

Question 3

examples of B2 Agonists

Answer 3

salbutamol, terbutaline (short acting), salmeterol, formoterol (long acting)

Question 4

anticholinergics

Answer 4

• Inhibit muscarinic receptors (M1/M2/M3), therefore relaxing smooth muscle and inhibiting mucus secretion. Also inhibits PNS impulses by selectively blocking M2receptors. Decreases spasms.
• Treatment of asthma, COPD, allergic rhinitis
• Side effects: Reduced secretion = dry mouth, throat, Reduced SM contraction = urinary retention, constipation, Reduced vagal tone = headaches, nausea
• Inhaling rather than oral = reduced side effects

Question 5

examples of anticholinergics

Answer 5

ipotropium bromide (short acting), tiotropium bromide (long acting)

Question 6

xanthines

Answer 6

Inhibits phosphodiesterases therefore increased cAMP, therefore relaxes smooth muscle. May alsoblock receptor for adenosine, preventing airway narrowing May also exert anti‐inflammatoryaction by blocking PDE in inflammatory cells.

• Treatment of COPD
• Side effects: tachycardia, palpitations, nausea; monitor plasma concentration.

Question 7

xanthines examples

Answer 7

theophylline, aminophylline

Question 8

corticosteroids

Answer 8

Endogenously produced in adrenal cortices, involved in a wide range of physiological responses:
- Decreases eosinophil action/cytokine formation (especially those that recruit/activate eosinophils)
- Inhibits generation of vasodilators
–inhibits COX2 induction
- Inhibits and resolves inflammatory responses, reducing oedema.
- Treatment of asthma, COPD, rheumatoid arthritis, IBD

Question 9

side effects of corticosteroids

Answer 9

hyperglycaemia, osteoporosis, proximal myopathy, skin thinning, weight gain, altered body fat distribution, hypertension, growth suppression in children, viral/fungal infection susceptibility increased

Question 10

examples of corticosteroids

Answer 10

prednisolone (oral), beclomethasone (inhaled), hydrocortisone (topical)

Question 11

leukotriene antagonist

Answer 11

• eg - monteleukast
• reduces airway narrowing and mucous production usually caused by leukotrienes
• Treatment of exercise induced asthma, seasonal allergic rhinitis
• Side effects: abdominal pain, thirst, headache, hyperkinesia, hypersensitivity (vasculitis), increasedinfectionrisk, muscle aches, liver damage

Question 12

mast cell stabilisers

Answer 12

eg - cromoglicate

• Stabilises mast cells and reduces release of histamine, prevents airway inflammation
• Treatment of asthma, conjunctivitis, allergic rhinitis
• Side effects: local irritation (cough), transient bronchospasm