3- Asthma Flashcards
What drugs prevent bronchoconstriction (early phase treatment)
Beta Agonists
Theophylline
Anticholinergics
Mediator antagonists
What meds prevent irritation reactions
Lipooxygenase and LT inhibitors
What are phosphodiesterases
Enzymes that degrade cyclic nucleotides (cAMP)
What is asthma
episodic ro chronic airflow obstruction that is reversible (per PFT)
Pathologic changes in bronchus due to asthma include
Narrow lumen BM hypertrophy Mucus plug Constriction Inflammatory cells cause edema
What happens in the 3 phases of asthma
Minutes: Mast cells release inflammation cells and cause bronchoconstriction
Hours: Neutro, Eosino, Macro, and Monocytes cause submucosal edema
Days: Eosino and lymphocytes cause epithelial damage and increase mucus
What is the MOA of Beta 2 Agonists
Stimulate adenylyl cyclase= increased cAMP= bronchodilation
What are the Beta 2 Agonists
Short: albuterol, terbuterol, metaproterenol
Long: Salmeterol, formeterol, indacaterol
What are side effects of beta 2 agonists
Tremor, tachycardia
Long acting: also CV events
What is the MOA of theophylline (Methylxanthine)
Inhibits PDE= increased cAMP= bronchodilation
Blocks adenosine
(increases diaphragm strength in COPD)
What is unique about the clearance of Theophylline
it varies with age;
Highest in young teens
High in smokers
What is Theophylline used for
Asthma prophylaxis against night attacks
Side effects of Theophylline are
Insomnia Tremor Anorexia Seizures Arrhythmias
How do Caffeine and theobromine work
Caffeine: similar but W/ increased CNS effects
Theobromine: similar but W/ increased cardiac effects
What can help reverse the cardiac effect of Theophylline
Beta blockers!
What is the MOA of anticholinergics
Competitively block muscarinic receptors= no Vagal bronchoconstriction
What are the Anti-muscarinics
Atropine (belladonna alkaloid)
Ipratropium (SAMA)
Tiotropium (LAMA)
Side effects of antimuscarinics are
dry mouth
cough
How do corticosteroids work
Block phospholipase A2= decrease in Arachidonic acid
Inhibit COX2
decrease mediator release (LT)
Increase B adrenoreceptor response
What are side effects of corticosteroids
Pharyngeal candidiasis
Adrenal suppression
Mild growth retardation in kids
What is Prednisone
systemic oral steroid for acute exacerbations/severe refractory asthma
Dexamethasone is most powerful
What are the aerosol corticosteroids
Beclamethosone
Budesonide
Flusonide
Fluticasone
What is prednisolone
IV corticosteroid for status asmathacus (+ hydrocortisone)
What are the effects of ICS
reduced mediator inflammation
How do Zafirlukast and Montelukast work
Interfere with LTD4 receptors and prevent exercise, antigen, and aspirin induced bronchospasm
*NOT for acute use
How does Zileuton work
inhibits 5-lipooxygenase = AA not converted to LT
prevents exercise, antigen, and aspirin induced asthma
What are the S/E of Zileuton
elevates liver enzymes
How does Cromolyn work
Decreases the release of mediators (histamine) from mast cells = prevents acute bronchospasm
When is cromolyn mainly used
for ophthalmic, nasopharyngeal, and GI allergies
for specific events, like going to a garden party
*not really used for prophylaxis
S/E of Cromolyn are
cough
What is the MOA of Omalizumab
anti-IgE Antibody; binds to IgE on mast cells and prevents activation
Omalizumab is used to
decerase frequency of exacerbations
S/E of omalizumab are
unknown; but it’s very expensive
What is the MOA of mepolizumab
Antibody to IL5 great for eosinophilic ashma
Sub-Q administration
Side effects of Mepolizumab are
increase in zoster- must be immunized with varicella zoster vaccine at least 4 weeks prior to starting med
When should you add SLIT
in adults with house dust mite sensitivity with allergic rhinitis if Sx not relieved with ICS and FEV1 is >70%
What are the step treatments GINA provides
1: SABA prn
2: + low dose ICS
3: + low dose ICS and LABA
4: Med/high dose ICS and LABA
5: Refer for add on Tx (tiotropium, anti-IgE, anti-IL5)
What does GINA recommend for most patients
low dose ICS- even if Sx are infrequent, they’ll help reduce risk of exacerbations
