Asthma Treatment Flashcards
How do Beta adrenergic receptor agonists work?
Bronchial SM relaxation; inhibits mediaor release (leukotrienes, prostanoids, Ach, small granule proteins)
Adenyla cyclase increase cAMP, increase in PKA, so Increased Na/K pump activity, increased K+ release; soidum calcium exchange.
Increases cilia beating frequency.
What are side effects of BARA’s?
Increase heart rtae, can cause tremor of skeletal muscle
How can BARA’s be administered?
Orally, inhalers and direct endotracheal
How can these BARA’s be classified?
Rapid or slow onset and short or long duration of affect.
Common ones, Salbutamol, a fast onset short acting.
What are features of rapid onset short acting BARA’s?
Last 4-6 hours and are most effective for first 30 mins. Use on a ‘as needed basis’. Can cause tremor, tachycardia and hypokalemia. Also tachyphylaxis.
What are features of long lasting BARA’s?
More of a preventer and taken regularly. Can be combined with glucocorticoids. eg salmeterol (slow onset) or formoterol (rapid)
What do anti cholinergic agents do?
Block Ach receptors preventing bronchoconstriction and mucus secretion. Act on all receptors. (muscarinic receptors).
NB can reduce mucociliary clearance or cause dry mouths.
What are two anticholinergic agents?
Atropine/ipatropium bromide(slow onset, short duration 6-8 hours) Tiotropium bromide (slow onset, long duration)
What do xanthine drugs (such as theophylline) do?
inhibit phosphodiesterase activity, preventing cAMP breakdown, prolonging bronchodilation.
Note that also has non selective adenosine receptor ANTAGonism. This can cause arrythmia and CNS stimulation.
What can be said about theophylline?
A narrow therapeutic range. Also impaired clearnace with heart problems and smoking
What simply do glucocorticoids do?
Reduce inflammation. They bind to GCR’s.
How do GC’s work?
They bind the the GCR in the cytosol, and act as a transcription factor. They thus inhibit cells releasing cytokines in inflammatory cells (dendritic, mast cells, eosiniphils) as well as inflammatory peptides and mediators.
How can inhaled GCs help?
decrease asthma symptoms and reduce use of bronchodilator! May take a few weeks to months to see improvement.
What are some examples of oral GC’s?
Prednisone- active form prednisolone, will increase gluconeogenesis.
Dexamethosone- active form methylprednisolone.
What are some adverse affects of oral GC’s?
Osteoporosis; increase BP; cushings syndrome (hypercortisolism)
