Bronchodilator Therapy-Singer Flashcards
What are the cellular mechanisms of asthma?
- allergen goes to dendritic & mast cells
dendritic cells activate th2 cells & mast cells activate eosinophils
eosinophilia
get some neutrophils too - smooth muscle hypertrophy & hyperplasia
- mucus plugs from goblet cell hyperplasia
- nerve activation–>epithelial shredding & bronchoconstriction
epithelial leakiness & edema in lungs.
What is the FEV1 like for the following asthma patients?
mild
moderate
severe
mild: FEV1 greater b/c a little smooth muscle hypertrophy w/o all the other complications yet
moderate: FEV1 lower, fibrosis begins
severe: FEV1 very low
Which levels of asthma are bronchodilators & corticosteroids most helpful for?
mild-moderate
hard to help severe asthmatics
T/F Smooth muscle is a distinct part of the asthma, completely separate from the immune process.
False. It is a part of the immune process.
Describe the basics of COPD.
Emphysema & Chronic Bronchitis
bronchioles disintegrate & alveolar walls are destroyed
clogged with mucus, but no inflammatory component
T/F First line treatment for COPD is corticosteroids.
False. no inflammatory component to this disease, so it doesn’t really help.
HOw do epigenetics play a role in asthma?
environmental exposure of parent can lead to epigenetic modification that is inherited by child & causes asthma
including: covalent modification of cytosine in CpG dinucleotides
* **maternal alleles appear to matter more.
What must you keep in mind when you decide on doses of inhaled drugs for asthma?
80% of the drug will be ingested instead of inhaled–>potential systemic effects
What were the first drugs used in asthma pre-1900?
beta agonists: ephedrine
anticholinergics
black coffee (caffeine similar to theophylline)
When did corticosteroids begin being used for asthma treatment?
around the 1950s
WHat are methylxanthines & where are they used in the world for asthma treatment?
theophylline
aminophylline
these are cheap & are used in other countries b/c of risk for seizures
What are some important examples of beta 2 adrenergic agonists? What are they all derivatives of?
albuterol
formoterol
salmeterol
**all derivatives of NE or epi
WHat is the MOA of beta 2 adrenergic agonists?
activates beta 2 receptor on muscle cells of lung
G-protein coupled receptor, activates adenylyl cyclase
increase in cAMP
activates PKA
lowers intracellular calcium
vasodilation
What are some other good effects of beta adrenergic agonists?
Prevention of mediator release from mast cells.
Prevention of microvascular leakage and edema.
What are some maybe not so good effects of beta adrenergic agonists?
Increase in mucus secretion from submucosal glands and ion transport across airway epithelium.
Reduction in neurotransmission in human airway cholinergic nerves by an action at presynaptic b2 receptors to inhibit acetylcholine release.
What are some short acting bronchodilators (SABA)? How long do they work for? How should they be used?
albuterol
3-4 hours
can be used 4-6X/day
used for acute attacks
What are some long acting bronchodilators (LABA)? How long do they work for How should they be used?
salmaterol
formoterol
last more than 12 hours
taken BID w/ inhaled corticosteroid
Can a LABA ever be used w/o ICS?
Yes, for COPD.
What are some important side effects for beta 2 agonists?
Muscle tremor Tachycardia Hypokalemia Restlessness Hypoxemia
Increased mortality with LABA
What is an important potential side effect of theophylline?
seizures refractory to AEDs
What are some examples of methylxanthines, still in the category of bronchodilators?
xanthine
theobromine
theophylline
caffeine
What is the MOA of theophylline?
inhibits phosphodiesterases
keeps cAMP levels high for activation of PKA
If PKA is active–decreased intracellular calcium & bronchodilation