PHARM of COPD AND ASTHMA Flashcards
what do M2 receptors do?
they are autoreceptors that respond to ACh, provide negative feedback for M3 receptors
why arent muscarinic antagonists as effective as beta agonists?
they only work in the large airways (which is not the site of the greatest resistance)
what protein can bind M2 receptors and make them dysfunctional?
major basic protein made by eosinophils
albuterol MOA
newer selective beta 2 agonist “rescue medication” causes bronchodilation for early asthma response
how fast does albuterol work?
quick onset w/ 3-6 hr duration
Name the newer long-acting beta2-agonists that are together w/ inhaled steroids
salmeterol xinofoate
salmeterol fluticasone (advair)
formoterol fumarate
formoterol fumarate + budesonide (symbicort)
what is the onset and duration of action of the long acting beta2 agonists?
slower onset, 12 hr duration
what is the MOA of the sympathomimetics?
increase levels of cAMP (causing bronchodilation)
inhib. effect on release of mediators from mast cells
some inhib. effect on microvascular permeability
promotes mucociliary transport
name an antimuscarinic drug
Ipratropium
what are some adverse effects of the sympathomimetics?
N/V & headache
fall in BP, increased HR & arrhythmias
PaO2 may decrease
CNS effects like agitation convulsions, coma, resp. and vasomotor collapse
adverse effect of ipratropium?
pupillary dilation and cycloplegia
how do antimuscarinic drugs like ipratropium work?
competitive ACh block
reduce smooth muscle constriction
decrease mucous secretion
enhance beta-2 mediated bronchodilation
what is combivent and what does it treat?
anti-cholineric (ipratropium) and beta-2 agonist (albuterol), combined therapy has greater improvement, treats COPD
How does theophylline work?
increases levels of cAMP by inhibiting PDE (vasodilation), and blocks adenosine receptors (which would normally produce vasoconstriction)
-anti-inflamm., inotrope, chronotrope, increased CNS activity
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what are some adverse effects of theophylline at low doses?
5-10 micrograms, may cause N/V, nervousness, headache, insomnia
what are some adverse effects of theophylline at higher doses?
serum greater than 20 micrograms/mL vomiting hypokalemia hyperglycemia tachycardia arrhythmias tremor neuromuscular irritability and seizures
how do cromolyns work?
alters chloride ion channels
prevents degranulation of mast cells in lung
inhibit inflamm. response by acting on eosinophils
inhib cough by action on nerves
reduce bronchial hyperactivity associated w/ exercise and antigen-inhaled asthma
When are cromolyns used in time course of disease?
prophylactically
MOA of glucocorticoids
- binds to GRalpha and translocates to nucleus
- uses GRE to transcribe anti-inflamm. genes
- recruits HDAC to block transcription of inflamm. genes
- causes trancription of TTP which destablilizes inflamm. mRNA
what are the pharmacologic effects of glucocorticoids?
- decrease prod. of inflamm. cytokines
- reduce mucus secretion
- reduce bronchial hyperactivity
- enhance effect of beta-2 agonists
what are some side-effects of inhaled corticosteroids?
oropharyngeal candidiasis
decreased bone density in premenopausal women
decreased growth in children
MOA of monteleukast
LTD4 receptor antagonists
- decrease bronchial reactivity and bronchoconstriction
- mucosal hypersecretion and mucosal edema
- decrease airway inflamm
what are some systemic side-effects of steroids therapy?.
glucose intolerance cushing syndrome cataracts immunosuppression retarded growth bone demineralization
adverse effects of monteleukast
GI probs laryngitis pharyngitis otitis sinusitis
how does zileuton work?
blocks the 5-LO path preventing the synth. of LTs
- decreases smooth muscle contraction and blood vessel perm.
- reduces wbc migration to the damage area
what are some adverse effects of zileuton?
CYP1A2 interacts w/ theophylline
hepatic enzyme elevation
MOA omalizumab
anti-IgE mAb, prevents release of inflamm. mediators–>decreased allergic response
what are some important treatment options for COPD pts?
- nicotine replacement therapy (nicotine causes dopamine release=pleasure)
- bronchodilators
- antimuscarinics
- theophylline
- combination therapy
- corticosteroids
- O2 therapy
- mucolytics
why dont you give sedatives to pts w/ airway disease?
depress respiratory drive
why dont you give beta blockers to pts w/ airway disease?
negative inotropic effect on heart, nonspecific interaction will cause bronchoconstriction of airway
why don’t you use local anesthetics w/ epinephrine on pts w/ airway disease?
epinephrine causes bronchodilation, vasoconstriction and tachycardia
why dont you give aspirin and NSAIDs to pts w/ airway disease?
block COX and shunt pathway to produce LTs which cause bronchoconstriction
why dont you give ACE inhibitors to pts w/ airway disease?
stops the breakdown of bradykinin (stimulates cough)
what is beclamethasone?
inhaled corticosteroids
what is prednisolone?
oral corticosteroid
explain the pathogenesis of asthma with eosinophils
eosinophils (late response) secrete major basic protein–>binds M2 receptors and makes them dysfunctional–>too much ACh–>bronchoconstriction
what are some adverse effects of ipratropium
pupillary dilation and cyloplegia on contact
what are the pharmacologic effects of omalizumab?
reduces severity and freq. of asthma attacks
-requires inhaled steroids which improves long term asthma control
