Respiratory Pharmacology Flashcards
what is asthma
reversible airway obstruction as a result of bronchial hyper-reactivity, airway inflammation, mucous plugging, and smooth muscle hypertrophy
how does bradykinin cause an increase in cough
- increase prostaglandins (PGE2-PG12)
- increase leukotrienes
- increase histamine
- activate type J receptors at peripheral vagal afferent endings/ non myelinated or C fibers
drug used to diagnose asthma
methacholine
inadequate surfactant lead to RDS so how then can that be prevented in women about to give birth
give them dexamethasone (glucocorticoids)
test used to check fetal lung maturity
lecithin to sphingomyelin > 2 in amniotic fluid indicates matured fetal lung
drugs used in asthma
bronchodilators: beta 2 agonists, antimuscarinics, methylxanthines
anti inflammatory agents: corticosteroids, leukotriene inhibitors, mast cell stabilizers, anti IgE antibody
beta 2 adrenergic agonists (classify by short acting for acute and long acting for non acute symptoms)
short acting: albuterol, pirbuterol, and terbutaline
long acting: salmeterol and formoterol
long acting beta 2 agonists can be taken in combination with what for control and prevention of symptoms in moderate to severe persistent asthma
inhalational corticosteroids
drugs used for exercise induced bronchoconstriction (EIC)
short acting beta 2 agonist
long acting beta 2 agonist
montelukast
adverse effects of beta 2 agonists
- most common: tremor, tachycardia, arrhythmias, hyperglycemia
- tolerance with excessive use
- paradoxical bronchospasm
anticholinergics that are used as bronchodilators and conditions they are used
ipratropium - short acting for asthma, QID (4 times a day)
tiotropium - long acting for COPD
mechanism of anticholinergics in bronchial SM
parasympathetic stimulation –> bronchial constriction and mucous secretion so anticholinergics block the muscarinic receptors in SM –> bronchial dilation of airway
adverse effects of ipratropium
dry mouth
caution with glaucoma, BPH, and bladder neck obstruction
methylxanthines used to treat asthma
theophylline
aminophylline
mechanism of methylxanthines (name them again)
theophylline and aminophylline
inhibit phosphodiesterase hence increasing cAMP –> bronchodilation
also block adenosine receptors
drugs that increase theophylline plasma levels
cimetidine, erythromycin, and ciprofloxacin
drugs that decrease theophylline plasma levels
phenytoin, phenobarbitone, and carbamazepine
complications of theophylline overdose
tremor, insomnia, GI distress, nausea, hypokalemia, hyperglycemia
seizures and arrhythmias
corticosteroids used in asthma
BF2 DP
beclomethasone budesonide fluticasone flunisolide dexamethasone prednisolone
drug given for uncontrolled allergic asthma
omalizumab
what is corticosteroids relationship to beta receptors
it increases beta 2 responsiveness and help reduce the need for beta 2 agonists
prevent remodeling of the respiratory tract
adverse effects of inhaled corticosteroids (ICS)
- more limited than systemic steroids
- cough, oral thrush, and dysphonia (difficulty speaking)
what are the systemic corticosteroids and their importance
- dexamethasone and prednisolone: life saving in status asthmaticus
- oral glucocorticoids: short course used for exacerbations with incomplete response to beta 2 agonists
adverse effects of systemic corticosteroids and how do you minimize these effects
abnormalities in glucose metabolism increased appetite weight gain hypertension adrenal suppression
limiting systemic therapy to few days
risk of uncontrolled asthma in pregnant women
pre eclampsia
perinatal mortality
pre term labor
low birth weight
hence tx pregnant woman with asthma as aggressively as women who are not preggo
effects of inhaled corticosteroids during first trimester
congenital abnormalities
endocrine and metabolic abnormalities
leukotriene inhibitors
zileuton
zafirlukast
montelukast
mechanism of leukotriene inhibitors
either block synthesis of leukotrienes or block the leukotriene receptors
- zileuton inhibits 5-LOX which forms leukotriene from arachidonic acid
- zafirlukast and montelukast are LTD4 receptor antagonist
clinical uses of leukotriene inhibitors (name them again)
zileuton, zafirlukast, montelukast
- prevent exercise, antigen, and aspirin induced asthma
- prevent bronchoconstriction and airway inflammation long term but not useful in acute bronchospasm
adverse effects of zileuton
elevated liver enzymes
adverse effects of zafirlukast and montelukast
vasculitis and systemic eosinophilia resembling churg strauss
what is omalizumab
anti IgE antibody (on mast cells) that prevents activation by triggers - prevents release of LTs and other mediators
uses of omalizumab
prophylactic management in asthmatic pts
and in cases of inadequate control with ICS
adverse effects of omalizumab
causes anaphylaxis - life threatening systemic allergic rxn
release inhibitors used in asthma
cromolyn
nedocromil
mechanism of release inhibitors in asthma (name them again)
cromolyn and nedocromil
prophylactic agent that stabilize the membrane of mast cells and prevent release of inflammatory mediator
uses of cromolyn and nedocromil
not for acute attacks of asthma
pretreatment blocks allergen and exercise induce bronchoconstriction
prevents food allergy and hay fever
adverse effects of cromolyn
infrequent laryngeal edema
cough
wheezing
adverse effects of nedocromil
unpleasant taste
