Pharm of agents in pulmonary med I Flashcards
How do beta receptor agonists work? what is their class?
class: bronchodilator
MOA: increase adenylyl cyclase, increase cAMP, PKA –> smooth muscle relaxation and bronchodilation
also increase ciliary beat frequence and some minimal anti-inflammatory effects
When are beta receptor agonists useful
acute attacks (rescue inhaler). Do NOT help with late onset response and do NOT prevent airway inflammation
what is dynamic dose response of beta agonists?
in acute exacerbations, the dose response curve for beta agonists shits to the right- you need more med to get the same response
Why is beta agonist selectivity important and what should we select for?
select for beta 1 receptors
important to decrease side effects of beta blockers in the heart
adverse effects of beta agonists
tachycardia, arrhythmias, tremor, hypokalemia, vasodilation, increased mortality with LABAs
how do we use beta agonists for asthma
good for acute exacerbations.
allbuterol (SABA) is good for PRN needs
LABAs like salmeterol and fomaterol are second line drugs when used in combination with corticosteroids
Corticosteroids: summary
most important drugs for asthma treatment
multiple and complex effects on airway inflammation
controls gene expression through interactions with regulatory proteins. help to reduce late onset asthma effect by decreasing inflammatory response
MOA of corticosteroids
remember that acetylated histones yield more active transcription of DNA. dimerized steroids enter the nucleus and activate acetyltransferases that enable acetylation of histones and expression of anti-inflammatory proteins. lower dose corticosteroids enter as monomers and inhibit histone acetyl transferase to prevent the expression of inflammatory proteins.
Corticosteroid effects on inflammatory cells
decrease eosinophil number decrease cytokines from T lymphocytes, which decrease eosinophils and mast cells decrease mast cells decrease macrophage cytokines decrease dendrite cells
corticosteroid effects on structural cells
decrease cytokins and mediators in epithelial cells
decrease leak from endothelial cells
increase B2 receptors and decrease cytokines on airway smooth muscle
decrease mucus secretion from mucus glands
onset of action for coritcosteroids
4-12 hrs after PO or IV injection. Bronchiol hyperreactivity reduced over 1-4 wks
for inhalation, see a respone in 1-2 wks, best improvement in 4-8 wks, and the reversed bronchiole hyperreactivity over 1-3 months
major side effects of steroids. 3 most important ones
growth retardation, myopathy, osteoporosis, panreatitis, psyche symptoms, Na and H20 retention, decreased K, increased glucose, HTN, decreased wound healing/immune function, central redistribution of fat, cataracts, glaucoma
2 most importatn: decreased bone density, subcapsular cataracts, increased risk of orgal pharyngeal candidasis (fluticasone)
How are steroids used in asthma?
severe acute asthma relief. to prevent impending episode of severe asthma. best for short term use- 7-10 days, and no need to taper if only used short term
pharmacogenomics of corticosteroids
GLCC1 gene