Respiratory Drugs Flashcards
Histamine receptors
H1 - mediates vasodilation and bronchoconstriction. Gq
- H2- Located in GI, Gs, lead to gastric acid secretion
- H3 is autoreceptors
H1 1st generation
Diphenylhydramine, chlorpheniramine
- Histamine receptor blockers decrease nasal discharge and bronchoconstriction
- Also have significant alpha and muscarinic blocking properties leading to side effects (CCC) Convulsions, Cardio, Coma (Rare to be this extreme)
- Used for allergy, motion sickness, sleep aid.
- Can also treat parkinson symptoms associated with antipsychotics
H1 Second Generation
-Loratadine, ceterizine, fexofenadine
- Inhibit H1 receptors, used for allergy,
- Don’t cross BBB and have no sedative S/E
Albuterol
- Short acting beta 2 agonist used for treatment of acute attack
- Binds to beta 2 receptor Gs leading to increase cAMP and bronchodilatoin
- Tachyphylaxis and palpitations are S/E
Salmeterol, Formeterol
- Long acting beta agonists
- Same action as albuterol but longer half life
- Increased risk of arrythmias and tremor
- Not used as monotherapy
Theophyline
- Methylxanthine that antagonizs PY adenosine receptor
- Leads to decreased vasodilation and also has PDE activity to incerase intracellular cAMP levels
- Narrow theruputic index and causes neuro and cardiotoxicity, so rarely used
- Blocks adenosine actions (SVT)
Ipratropium
- Inhaled muscainic competitive antagonist that decreases bronchoconstriction
- M3 receptors are responsible for bronchoconstriction Gq
- M2 is Gi on cardiac and M1 is Gq on glands
- Minimal systemic effects when inhaled
- Used to treat asthma and COPD
Tiotropium
-Similiar action on M3 receptors, but longer half life
Fluticasone, Beclomethasone
- Inhaled steroids used as first line treatment for asthma prevention
- Cause decrease cytokine production anad reduced inflammation (NFkb)
- May cause oral thrush
Montelukaust, Zafiralukast
- Competetive antagonist at leukotriene receptors
- C5, D5, E5, mediate bronchoconstriction
- B5 mediates neutrophil chemotaxis
- Used especially for aspririn induced asthma
Zilueton
-Inhibits 5 lipoxygenase pathway and reduces leukotriene production from arachadonic acid
Cromylyn
- Stabalizes mast cells and prevents histamine release
- Histamine causes bronchoconstriction and vasodiltion seen in acute phase of asthma attack
Omalizumab
- monoclonal antibody to serum IgE
- Lowers effective IgE concentraion that will reduce likilhood of crosslink on mast cells
- Used in asthma that is resistant to steroids and beta agonists
Guaifinesin
-Expectorant that thins respiratory secretions
N-Acetlycysteine
- Forms disulfie bonds and disrupts mucus plugs in CF patients
- Also used to regnerate reduced glutathione in acetomenaphin poisoning
Bonsentan
- Endothelin 1 antagonist
- Prevents vasoconstriction in pulmonary hypertension
Dextromethorphan
- Coedeine analog that works as an antitussive
- Antagonizes NMDA receptor decreasing cough reflux
- Mild opiod effects, if overdose treat with naloxone
Pseudophedrine, phenylephrine
- alpha agonist (sympathomimetic) in the nasal mucosa cause constriction and decresed rhinorrhea and can open eustachian tubes
- Have stimulant effects and may cause CNS stimulation and anxiety
- Also hypertension
Methacholine
-AchR agonist and used to provoke asthma to clinically diagnose
