Asthma Flashcards
Asthma Tx Strategies (2)
- Dilate airways
- Decrease inflammation
- Prevention
Bronchioles are constricted by _____
- Cholinergic innervation
Bronchioles are relaxed by _____
- Beta 2 receptors
Used to dx asthma
Methacholine Challenge
B agonists MOA
- B2 receptors relax airway and inhibit histamine release
B agonist Admin
- Inhaled/aerosol
- Oral
- Injected in emergency
Selective B agonists- SABA, LABA
SABAs: Albuterol, Levalbuterol, Pirbuterol
LABAs: Salmeterol, Formoterol
SABA t 1/2 and Admin
4 - 6 hrs
- Act IMMEDIATELY (stops attack in progress)
- Usually inhaled
LABA Tx (2)
- Prevention and prophylaxis asthma
- Decrease nocturnal asthma
LABA t 1/2
- Effect takes 20-30 min
LABA should always be combined with _____
Steroid (Advair)
- to prevent down regulation and increase sensitivity
B2 agonist SE (4)
- Tachycardia
- Nervousness
- Dizziness
- Tremor (more with oral)
Bronchodilators (3)
- Ipratropium
- Tiotropium
- Theophylline
Ipatropium MOA
- Muscarinic Antagonist
Ipatropium Admin
- Inhaled, poorly soluble, not absorbed
Ipatropium Tx
- COPD
- Useful for pts intolerant to B2 agonists
(often combined with albuterol)
Theophyline MOA (3)
- Increases cAMP phosphodiesterase inhibitor
- Blocks adenosine receptor
- Relaxes smooth muscle, stimulates CNS and heart
Theophyline Tx
- Asthma not controlled by B agonists
Theophyline SE (5)
- CNS: nervousness, insomnia, anxiety, tremor
- Cardiac: tachy, arrhythmias
- Muscle: decreases diaphragm fatigue, increases contraction
- Weak diuretic
- OD: palpitations, HA, N/V, seizures –> Low therapeutic index (blood level important)
Anti-inflammatory Drugs (3)
- Corticosteroids
- Leukotriene Inhibitors
- Cromolyn sodium
Anti-inflammatory Drugs (3)
- Corticosteroids
- Leukotriene Inhibitors
- Cromolyn sodium
Corticosteroids MOA (3)
- Decrease inflammation
- Reduce bronchial reactivity
- Improve response to B agonists
Corticosteroid Tx
- First line asthma (inhaled corticosteroids)
- Use orally in severe asthma or exacerbation
Corticosteroid SE (2)
- Thrush
- Hoarseness
Leukotriene Inhibitors (4)
- Zileuton
- Zafirlukast
- Montelukast
- Pranlukast
Zileuton MOA
- Inhibits 5-lipoxygenase
Pranlukast MOA
- Leukotriene receptor antagonist
Leukotriene Inhibitors Tx
- No effect on attack in progress
- May allow decreased steroid dose
- May decrease aspirin-sensitive asthma
Leukotriene Inhibitors SE (3)
- URI, sore throat, HA
- Abd pain
- Sleepiness
May cause psychiatric symptoms
- Montelukast
Cromolyn sodium, Nedcromil MOA
- Inhibits release of histamine from mast cells (NOT a bronchodilator)
Cromolyn sodium, Nedcromil Tx
- Mostly in children
- Prevention
Cromolyn sodium, Nedcromil Admin
- 4x/day, chronically
- Nasal OTC
- Tastes bad
Omalizumab MOA (3)
- Monoclonal antibody to IgE’s high affinity Fc receptor
- Prevents binding of IgE to cells associated with allergic response
- Lowers free IgE
Omalizumab Tx
- Mod - severe allergic asthma
H1 Histamine Receptor Found in (3) and acts through ____
- Smooth muscle, Endothelium, Brain
- Gq
- Allergic response
H2 Histamine Receptor Found in (3) and acts through
- Heart, brain, mast cells
- Gs coupled –> increase cAMP
- Gastric acid secretion
Effects of Histamine on Cardiovascular system (3)
- Vasodilation: H1 increases NO from endothelium; H2 receptor direct vasodilation
- Decrease BP, tachycardia
- Increase cap permeability –> edema and swelling
Effects of Histamine on Smooth muscle
- Bronchospasm (H1) - problematic asthmatics
Effects of Histamine on GI
- Increased gastric acid secretion (H2)
Effects of Histamine on GI
- Increased gastric acid secretion (H2)
Effects of Histamine on Skin
- Itch, pain, welt, sensory nerve stimulation
Triple Response
- Localized red spot, vasodilation
- Flush or flare, axon reflexes
- Wheel in 2-3 min, increased cap perm
Effects of Antihistamines (6)
- Inhibit smooth muscle response
- Inhibit vasodilation due to H1
- Inhibit flare and itch, wheal
- Inhibit salivary, lacrimal secretion
- CNS depression, stimulation
- Counter motor sickness
H1 Antagonists Sedating (4)
- Diphenhydramine (Benadryl)
- Hydroxyzine
- Dimenhydrinate (Dramamine)
- Promethazine
2nd Gen H1 Antagonists (6)
- Loratidine
- Desloratidine
- Levocetirizine
- Certirizine
- Acrivistine
- Fexofenadine
Motion Sickness H1 antagonists (2)
- Diphenhydramine
- Dimenhydrinate
Antiemetic/motion sickness H1 antagonist
- Promethazine
2nd Gen H1 Antagonist Features (3)
- Do not enter brain well so less sedation
- Do not have anticholinergic effects
- Not useful for motion sickness
H1 antagonists excreted directly by kidney
- Cetirizine
- Acrivastine
- Levocetirizine
H1 antagonist Tx
- Allergic rhinitis (prophylactic)
- Seasonal itching/conjunctivitis
- Itching and hives
- Motion sickness 1st gen (prophylactic)
- Sedation 1st gen
- Dry up secretion 1st gen
1st Gen H1 antagonist SE (7)
- SEDATION
- Anticholinergic
- CNSL dizziness, blurred vz, excitement, restlessness, insomnia
- GI: N, anorexia, increased app
- Possibly teratogenic
- Allergic rxn - topical
- DECREASE SEIZURE TRESHOLD
Interactions with 1st Gen
- CNS depressants
Interactions with 2nd Gen
- Erythromycin, ketoconazole
- Grape fruit juice
- Cimetidine (inhibit their metabolism)
1st Gen OD
- Similar to atropine poisoning
- Sedation
2nd Gen OD
- Cardiac arrhythmias
- Sinus tachy
2nd Gen OD
- Cardiac arrhythmias
- Sinus tachy
Histamine Release Inhibitors (3)
- Cromolyn
- Azelastine
- Cetirizine
