Pharmacology Flashcards
inhaled corticosteroid for anti-inflammatory effect
affect airway responsiveness/reactivity
maintenance drugs for asthma
short acting bronchodilators and IV/PO corticosteroids
affect airway resistance
rescue medications for asthma
Systemic corticosteroid
Asthma exacerbations (short term)
IV in status asthmaticus
After the patient has improved, drug is withdrawn over 1-2 weeks, transfer to inhaled corticosteroid for maintenance
adverse effects: suppression of the HPA axis with systemic administration (bone resorption, skin thinning, growth retardation)
Methylprednisolone
Short acting beta2 adrenergic agonist
Asthma exacerbations
Relax airway smooth muscle (beta2 receptors present but not innervated) leads to bronchodilation
Beta2 selective due to sidechain characteristics
Inhibit release of mast cell mediators (inhibit microvascular leakage and increase mucociliary transport)
Rescue medication
Increases glucocorticoid receptor nuclear translocation (enhancing effect of glucocorticoid)
Acts in 3-5 minutes, peak action in 30-60 minutes, duration of action 3-6 hours
If used more than twice a week, asthma is not controlled
adverse effects: Muscle tremor, tachycardia, hypokalemia (uncommon)
Albuterol
Long acting beta2 adrenergic agonist
Asthma control only with inhaled corticosteroid (controls most asthma)
COPD (can be used alone)
Relax airway smooth muscle (beta2 receptors present but not innervated) leading to bronchodilation
Inhibit release of mast cell mediators (inhibit microvascular leakage and increase mucociliary transport)
maintenance medication
increases glucocorticoid receptor nuclear translocation (enhancing effect of glucocorticoid)
duration of action more than 12 hours
adverse effects: Muscle tremor, tachycardia, hypokalemia, potential tolerance
Salmeterol
Short acting muscarinic antagonist
Limited use in asthma unless intolerant of beta2 agonists, potentially additive with beta2 agonists
COPD
Block the effects of ACh released by the vagus to M3 receptors –> decrease smooth muscle contraction, and mucus secretion –> bronchodilation
Not anti-inflammatory
Onset of action 15-30 minutes, duration of action 3-4 hours
adverse effects: Dry mouth
Few systemic effects because of poor absorption
May cause urinary retention – caution in BPH
Ipratropium bromide
Long acting muscarinic antagonist
Limited use in asthma unless intolerant of beta2 agonists, potentially additive with beta2 agonists
COPD
Block the effects of ACh released by the vagus to M3 receptors leading to decreased smooth muscle contraction, and mucus secretion which causes bronchodilation
Not anti-inflammatory
Duration of action more than 24 hours
adverse effects: Dry mouth
Few systemic effects because of poor absorption
May cause urinary retention – caution in BPH
Tiotropium
Non-selective phosphodiesterase inhibitor
COPD, asthma
Oral, less expensive
Inhibits cAMP phosphodiesterase in smooth muscle
Blocks activation of adenosine receptors on smooth muscle (decrease contraction) and mast cells (decrease histamine release)
Increase histone deacetylation (decrease cytokine synthesis)
Decrease cytokine release
Increases diaphragm contractility in COPD (may increase inhaled corticosteroid effect)
Narrow therapeutic window monitor plasma levels (clearance varies)
adverse effects: Nausea, vomiting, nervousness, anxiety, tremor, convulsion, vasodilation, tachycardia, arrhythmias
Theophylline
Leukotriene pathway inhibitor
Asthma, no role in COPD
Oral
Inhibits bronchoconstriction by binding to leukotriene receptors and blocking leukotriene binding and function
Add on treatment for patients with mild to moderate asthma that is not well controlled with inhaled corticosteroids
adverse effects: Hepatic dysfunction is rare and reversible on discontinuation – monitor aminotransferase activity
Montelukast
IgE inhibitor
asthma
Monoclonal antibody against IgE – binds the Fc region of IgE and prevents it from binding to Fc receptors and causing mast cell degranulation
SC every 2-4 weeks over 10 weeks
Dose is determined by IgE levels in the serum
Reduces the use of corticosteroids and prevents allergic rhinitis
expensive
adverse effects: Few side effects, possible anaphylaxis associated with injection of peptide
May be associated with increased risk of malignancy
Wide variation in response
Omalizumab
aerosol corticosteroid
most effective treatment in preventing asthma attacks
use in COPD is controversial, use if FEV1 is less than 50 percent with exacerbations (no apparent anti-inflammatory effect in COPD)
Suppresses inflammation by suppresses transcription of inflammatory genes (cytokines)
Increases the transcription of beta2 receptors on airway smooth muscle
does not cure the disease
Rapid anti-inflammatory effects (hours), maximal effects take weeks/months (most effective with daily use, decrease dose if possible)
Adding a long acting beta2 agonist is more effective than increasing dose
17 alpha substitution increases topical activity
Adverse effects: Oropharyngeal candidiasis and dysphonia when inhaled (gargle and spit to limit this),
minimal systemic effects when inhaled
suppression of the HPA axis with high inhaled doses or systemic administration (bone resorption, skin thinning, growth retardation)
Fluticasone
