Pharmacology Flashcards
How do asthma medications work? (2 ways)
Relax bronchial smooth muscle
Prevent and treat inflammation
What three types of nerve fibers innervate airways?
Sympathetic/adrenergic
Parasympathetic/cholinergic
Nonadrenergic, noncholinergic fibers (NANC fibers)
What does sympathetic stimulation cause in the airway?
Bronchodilation
What does parasympathetic stimulation cause in the airway?
Bronchoconstriction
What does NANC stimulation cause in the airway?
Stimulatory or inhibitory
What is the endogenous agonist for B2 receptors?
Epinephrine
Three indications for anticholinergic agents
Treatment of COPD
Treatment of acute asthma exacerbations
When B-agonist are contraindicated
What are the six bronchoconstricting peptides? (released by NANC fibers)
Neurokinin A Calcitonin gene-related peptide Substance P Bradykinin Tachykinin Neuropeptide Y
What two bronchodilators does NANC fibers release?
NO
VIP
What type of T cells does asthma trigger?
TH2
What does IL-4 induce?
B cells to produce exaggerated amounts of IgE
IgE binds to mast cells
What does IL-13 induce?
Causes goblet cell hyperplasia, increased mucus production, smooth muscle hyperplasia/hypertrophy
What does IL-5 induce?
Recruits eosinophils
What is ipratropium used for?
Astha not responsive to inhaled B2 agonist
COPD
Why is ipratropium better than atropine?
Not significantly absorbed
Minimal side effects
Ipratropium mechanism of action
Muscarinic antagonist
What long acting anticholinergic is used for COPD?
Tiotropium
and ipratropium
Terbutaline
B1, B2, or mixed selectivity?
B2
Albuterol
B1, B2, or mixed selectivity?
B2
Pirbuterol
B1, B2, or mixed selectivity?
B2
Biterol
B1, B2, or mixed selectivity?
B2
Isoproterenol
B1, B2, or mixed selectivity?
Mixed
Metaproternol
B1, B2, or mixed selectivity?
B2 selective with slight B1 action
Why are anti-asthma agents better in inhalant form? (such as albuterol)
Reduced systemic effects of drug
What can high doses of B2 agonist cause? And why?
Tremor because the receptors are expressed in peripheral skeletal muscles
What are formoterol and salmeterol?
Long acting beta agonist (LABA)
What is the advantage of LABA and why?
Have lipophilic side chain–>resist degradation
Used prophylaxis
What must be administered with formoterol and salmeterol? And why?
Corticosteroids because they dont treat inflammation
How do methylxanthines work?
Nonspecific inhibition of phosphodiesterase isoenzymes
Prevents cAMP degradation causing relaxation of muscle
Also inhibit inflammation
What are two methylxanthines?
Theophylline
Aminophylline
What receptor causes secondary effects of theophylline such as hypoxia?
Adenosine receptor antagonism
Why does theophylline have interactions with cimetidine?
Metabolized by P450 isoenzyme CYP3A
What is the best protective agent for asthma?
Inhaled corticosteroids
Why do corticosteroids have long term prophylactic effects?
Inhibit IL-4 and IL-5 reducing inflammation
Induce apoptosis on inflammatory cells
Reduced inflammation over time causes reduction in hyper resonsiveness and reverses features of asthma
What are the limitations of corticosteroids?
Do not sure astham, simply reduce inflammation
Does not reverse long term injury
What does substitution at the 17a position do to corticosteroids?
Increases topical absorption
What does cromolyn do?
Inhibits allergic response but does not relieve response once it begins
What do montelukast and zafirlukast do?
Inhibit binding of LTC4, LTD4, and LTE4 to CysLT1
What is the mechanism of omalizumab on asthma?
Decreases quantity of IgE and block remaining IgE from binding to mast cells
What patients should be treated with regular preventive therapy for asthma?
Patients with more frequent or severe symptoms, or with impairment in lung function
