Respiratory Flashcards
Define asthma
reactive airway disease; inflammation of bronchoconstriction, airway inflammation
MoAs of Asthma Drugs
drug MoA: bronchodilation, anti-inflammatory
Goals of Asthma Treatment
goals: Decrease impairment, Decrease risks (good sx control, minimal adverse effects)
First line Asthma Treatment
first-line: SHORT acting beta 2 agonists, INHALED corticosteroids
Classifications of Asthma
- Intermittent (least severe); 2. mild persistent; 3. Moderate persistent; 4. Severe persistent
Describe Intermittent Asthma
Least severe - <2d/wk - near normal peak flow
Therapy for Intermittent Asthma
no daily meds/chronic tx - short-acting beta 2 agonist (quick relief)
Describe Mild Persistent Asthma
>2d/wk but not daily - near NL peak flow
Therapy for Mild Persistent Asthma
low dose inhaled corticosteroids - short-acting beta 2 agonist
Describe Moderate Persistent Asthma
daily attack; 60-80% NL peak flow
Therapy for Moderate Persistent Asthma
low-to-med dose inhaled corticosteroids AND long-acting beta 2 agonist - short-acting beta 2 agonist
Describe Severe Persistent Asthma
continual attacks (multiple each day); <60% NL peak flow
Therapy for Severe Persistent Asthma
high dose inhaled corticosteroids AND long-acting beta 2 agonist - short-acting beta 2 agonist
Describe COPD
chronic, irreversible obstruction of airflow due to a combo of emphysema, chronic bronchitis, airway hyper-reactivity; associate w/ smoking
First-Line COPD Treatment
anticholinergics; beta 2 adrenergic agonists
Mild COPD Management
mild COPD - FEV1 >80% - add short-acting bronchodilator when needed
Moderate COPD Management
moderate COPD - FEV1 50-80% - add regular tx c 1+ bronchodilator (when needed) + rehabilitation
Severe COPD Management
severe COPD - FEV1 30-50% - add inhaled corticosteroid if repeated exacerbations
Very Severe COPD Management
very severe COPD - FEV1 <50% c chronic respiratory failure - add long-term O2 therapy + consider sx
allergic rhinitis
Attack typically is initiated by inhalation of an allergen causing mast cells to release inflammatory/allergic mediators
Sx of allergic rhinitis
sneezing, ithcing eyes/noes, watery rhinorrhea, nasal congestion
Tx of allergic rhinitis
ANTIHISTAMINES, alpha -adrenergic agonists, corticosteroids, cromolyn, montelukast
Inflammatory/Allergic Mediators
HISTAMINE, leukotrienes, chemotactic factors
beta 2 agonist activity
Bronchodilation; drug of choice for mild/intermittent asthma and used in episodes of acute bronchoconstriction; no anti-inflammatory effects
beta 2 agonist Adverse Effects
TREMOR, tachycardia, hyperglycemia, hypokalemia, hypomagnesemia; minimized c INHALATION and c beta 2 SELECTIVE meds
inhaled adrenergic agonists
Short-acting beta 2 agonists; Long-acting beta 2 agonists
Short-acting beta 2 agonist
Onset - 5-30 minutes; Duration 4-6 hr; drug - Albuterol
LONG-acting beta 2
monotherapy contraindicated (Increase risk asthma-related death); Slower onset of action and duration of 12 hrs
Other adrenergic agonists
Epinephrine
Epinephrine
Used as the drug-of-choice for severe bronchoconstriction (status asthmaticus) and acute anaphylaxis
Adverse Effects of Epinephrine
tachycardia; metabolic & GI abnormalities, CNS stimulation
inhaled corticosteroids - MoA
Control airway inflammation by blocking synthesis of arachidonic acid by phospholipase & inhibition of the expression of COX & leukotrienes
Most effective tx for long-term asthma control
Inhaled corticosteroids
Drug of choice for any degree of persistent asthma
Inhaled corticosteroids
Why use inhaled corticosteroids?
helps reduce the need for systemic use but results are technique dependent
Why is proper technique important with inhaled corticosteroids?
proper technique improves outcomes, Decrease adverse effects; use spacers
When and why are spacers used with inhaled corticosteriods?
Chamber reduces velocity causing deposit of large particles; Minimizes risk of adrenal suppression; RECOMMENDED FOR ALL PATIENTS, especially children and seniors
Adverse Effects of Inhaled Corticosteroids & Prevention Methods
oropharyngeal candidiasis and hoarseness; swish and spit water to prevent
Actions of Inhaled Corticosteroids
- Reverses mucosal edema 2. Decrease the capillary permeability 3. Inhibit the release of leukotrienes 4. Reduction of hyper-responsiveness of airway smooth muscle to stimuli
Method of administration for Systemic Corticosteroids
Oral
Describe discontinuation strategy for systemic corticosteroids and rationale
When symptoms are improved the medication is slowly discontinued for 1-2 weeks, due to HPA axi
Indications for systemic corticosteroids
Severe exacerbations of asthma
Adverse Effects of Systemic Corticosteroids
- CNS: emotional disturbances 2. Osteoporosis 3. Increased appetite/weight gain 4. Immunosuppression/Impaired wound healing 5. Hypertension, edema 6. Peptic ulcer disease 7. Hypokalemia 8. Hirsutism 9. Glaucoma 10. Stunted growth in pediatrics
Anticholinergics for Asthma
Traditionally not effective for asthma patients unless they also have COPD
Anticholinergics for COPD
1st line tx
leukotriene receptor antagonists
inhibit leukotriene-induced bronchoconstriction and inflammation via Inhibition of 5-lipoxygenase (an enzyme required for leukotriene synthesis)
Leukotrienes
inflammatory mediators causing bronchoconstriction, increased endothelial permeability, & mucus secretion
leukotriene receptor antagonist uses
prophylactic, moderate to severe allergic asthma
inflammatory cell stabilizers (*intranasal cromolyn) - MoA
inhibits mast cell degranulation and histamine release *blocking initiation of allergic rxn
Inflammatory cell stabilizers - Actions
asthma - pretreatment blocks allergen and exercise-induced bronchoconstriction, may take 4-6wks for full effect
methylxanthines
largely replaced by beta 2 agonists and corticosteroids
Why are methylxanthines rarely used?
NARROW THERAPEUTIC INDEX; potential for many drug interactions; may lead to fatal arrhythmias in OD
General MoA of Antihistamines
COMPETITIVE blockade of histamine-1 (H1) receptors
1st Gen Antihistamines
often provide better control of sx
Adverse Effects of 1st Gen Antihistamines
Increase sedation, Increase antocholinergic SE (xerostomia, urinary retention, blurred vision, sedation (drowsy, Decrease cognition)
2nd Gen Antihistamines
may NOT provide optimal relief of sx
Adverse Effects of 2nd Gen Antihistamines
Decrease sedation, Decrease ANTICHOLINGERGIC SE
MoA of alpha -adrenergic agonists
constriction of dilated arterioles in nasal mucosa and reduction of airway resistance
Uses of alpha -adrenergic agonists
short-term relief of nasal congestion
Dosing & indications of alpha -adrenergic agonists
nasal sprays; rapid onset of action; use limited to 3 days to prevent rebound congestion (and addiction)
Adverse Effects of alpha -adrenergic agonists
systemic - HTN; rebound congestion (with prolonged use)
Rhinitis medicomentosa
Rebound nasal congestion
Use of antitussives
analgesia, COUGH SUPPRESSANT (non-productive); Example - Benzonatate (Tessalon®)
Use of expectorant
help loosen phlegm and thin bronchial secretions to make cough more productive. Examples - Guaifenisin (Robitussin, Mucinex®, etc.)
Phospholipase
Enzyme converting phospholipids in cell membrane to Arachidonic acid
Drug category inhibiting activation of phospholipase
corticosteroids
Two enzymes acting on arachidonic acid
lipoxygenase; cycloxygenase (COX)
Two products produced from arachidonic acid
leukotrienes; prostaglandins
Inhibitors of arachidonic acid enzymes
NSAIDs; ASA (aspirin)
