Respiratory pharmacology Flashcards Preview

Module 9: Respiration > Respiratory pharmacology > Flashcards

Flashcards in Respiratory pharmacology Deck (10)
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1
Q

Describe autonomic control bronchial tone

A
  • No sympathetic innervation but is dilated by circulating adrenaline
  • has B2 adrenoceptors (increase cAMP in bronchial SM causing relaxation)
2
Q

Describe parasympathetic control of bronchial tone

A
  • muscarinic acetlycholine receptors
  • M3 (increase IP3 and intracellular Ca)
  • Causes constriction of bronchial SM
3
Q

How do PDE inhibitors cause relaxation of smooth muscle?

A

PDE inhibitors prevent PDE from decreasing the amounts of intracellular cAMP and gAMP. A build up of these will inhibit contraction and cause muscle relaxation.

4
Q

How can bronchodilation be acheived pharmacologically?

A

Drug targets:

  • B-adrenergic agonists
  • anticholinergic drugs
  • methylxanthines (PDE inhibitors)
5
Q

Why do we need to target drug delivery to the lungs?

A

To avoid any unwanted side effects. i.e. smooth muscle relaxation in other parts of the body

6
Q

What are the 2 main characteristics that a drug targeted to the lungs should have?

A

Poor lipid solubility and high water solubility

7
Q

Give an example of a B-adrenoreceptor agonist and when it might be used

A

Adrenaline (epinephrine) - emergency treatment of life threatening bronchoconstriction
e.g. terbutaline, salbutamol, salmeterol, clenbuterol

8
Q

What are the pharmacological properties of adrenaline?

A
  • Stimulates adrenergic pathways
  • Side effects - increased heart rate, palpatations; skeletal muscle tremors
  • Tolerance - rapid tolerance will occur if used repeatedly, suitable for intermittent use
9
Q

What are the properties of anticholinergic drugs, e.g. atropine?

A
  • Mechanism - block endogenous parasympathetic tone
  • Side effects - CNS stimulation, GI inhibition
  • Administration - topical
10
Q

What are the properties of methylxanthines?

A

e. g. theobromine, caffeine, theophylline, etamiphylline
- Mechanism - PDE inhibitors
- Decrease inflammatory mediators
- Side effects - GI; CVS stimulation; CNS agitation, nervousness, convulsions