10 - Respiratory Pharmacology Flashcards
What is the rationale for using inhaled medications for pulmonary disease?
- lower doses
- faster onset of action
- minimizes side effects by limiting systemic absorption
What are the types of inhaled medications? What meds are only available orally?
Inhaled:
- short/long acting beta agonists
- short/long acting muscarinic/cholinergic antagonists
- inhaled corticosteroids
Orally:
- leukotriene modifiers
What is albuterol’s mechanism of action?
- short acting beta-2 agonist (SABA)
- via adenyl cyclate, increases cAMP –> increases Ca2+ efflux
- relaxes smooth muscles (bronchodilation)
- has some beta-1 effects that lead to side effects
What are the side effects of albuterol?
Nonspecific Beta-1 side effects:
- tremor
- tachycardia
- hypertension
What is albuterol’s onset of action and duration?
Rapid onset (10-20 minutes) and moderate duration (4-6 hours)
Albuterol is a [short/long]-acting beta-2 agonist.
short
Salmeterol has a [slow/fast] onset and [short/moderate/long] duration.
slow onset, long duration
Formoterol has a [slow/fast] onset and [short/moderate/long] duration.
fast onset, long duration
Sympathetic stimulation causes [bronchoconstriction/bronchodilation]
bronchodilation
Because they are not anti-inflammatory, ___ should not be used as a monotherapy for asthma.
long acting beta-2 agonists
Anticholinergics/antimuscarinics block [sympathetic/parasympathetic] receptors, leading to [bronchoconstriction/bronchodilation].
block parasympathetic –> bronchodilation
What type of medication is ipratropium?
Short acting antimuscarinic (4-6 hours)
What type of medication is tiotropium?
Long acting antimuscarinic (24 hours)
What is the major side effect of antimuscarinics?
Dry mouth
What are the effects of theophylline? Why isn’t it commonly used anymore?
- bronchodilator
- anti-inflammatory
- respiratory stimulant
- improves respiratory muscle function
Has a narrow therapeutic range, significant toxicity, and is metabolized by cytochrome P450 (drug interactions)
How are leukotriene antagonists administered?
Orally
In what 2 ways do leukotriene antagonists work?
- inhibit 5-lipoxygenase (from creating leukotrienes)
- block leukotriene receptors
What are the effects of leukotriene antagonists? What type of asthma medication is it?
Mostly anti-inflammatory with some bronchodilating effects.
Used as a control medication to improve FEV1 and decrease airway eosinophils (also used in exercise-induced bronchospasm)
What are the principal effects of inhaled corticosteroids?
anti-inflammatory agents (decreases the amounts of lymphocytes, mast cells, and eosinophils and associated cytokines)
What is the mainstay anti-inflammatory medication for asthma?
Inhaled corticosteroids
What is the effect of Roflumilast?
PDE-4 inhibitor (increases cAMP) –> weak bronchodilator
What is the effect of Cromolyn?
block histamine and leukotriene release from mast cells
What is the effect of Nedocromil?
blocks histamine and leukotriene release from mast cells; blocks mediator release from eosinophils, macrophages, platelets
similar to Cromolyn
cAMP, which is formed using ___, leads to [bronchoconstriction/bronchodilation].
Adenylate cyclase creates cAMP from ATP –> bronchodilation
How do beta 2 agonists lead to smooth muscle relaxation?
Stimulate adenylate cyclase, which creates cAMP from ATP. cAMP build up leads to bronchodilation
What advantage does salmeterol have over albuterol in terms of administration?
It is inhaled as a dry powder, which is much easier than a spray (albuterol is a spray)
How do corticosteroids reduce inflammation?
They block phospholipases, which are the enzymes needed to convert arachidonic acid into the various inflammatory molecules –> has a broad anti-inflammatory effect because it blocks the beginning of the inflammatory pathway
What is the most common inhaled corticosteroid in the US?
Fluticasone propionate (Diskus)
How do leukotriene modifiers reduce inflammation?
They block the formation of leukotrienes or block leukotriene-receptor binding –> reduce the effects of leukotrienes (bronchoconstriction, mucus secretion, edema, eosinophil recruitment)
Acetylcholine leads to [bronchoconstriction/bronchodilation].
bronchoconstriction
How do muscarinic antagonists reduce bronchoconstriction?
they block acetylcholine from binding to muscarinic receptors, blocking parasympathetic bronchoconstriction
How does treatment differ for COPD and asthma?
Asthma requires corticosteroids/anti-inflammatory agents. COPD does not
What respiratory illness are monoclonal antibodies used for?
allergic asthma
What is the most important monoclonal antibody side effect?
hypersensitivity reaction, usually to humanized antibodies
