Chronic Rhinitis, Cough, and Cold Medications Flashcards
Where are cough receptors located?
- Larynx and supralarngeal area
- Trachea and bronchi
- Ear canals
- Pleura, pericardium and diaphragm
- Esophagus and stomach
What antitussives are centrally acting?
Dextromethorphan
Opiates
What antitussives are locally acting?
Benzonatate
What is the MOA of dextromethorphan?
Crosses the BBB and activates sigma opioid receptors on the cough center in the central nervous system (medulla), thereby suppressing the cough reflex
Does not affect ciliary activity (in the bronchial tree)
What are the indications for dextromethorphan?
Short-term relief of cough
What are possible interactions with dextromethorphan?
MAIOs and SSRI/SNRI’s, can cause serotonin syndrome
What are the contraindications for dextromethorphan?
Avoid in chronic cough, hepatic disease, and operating machinery
What is the MOA of Codeine?
Suppresses cough reflex centrally, dries bronchial secretions
What are the indications for codeine?
Short term relief of cough
Why should Guaifenesin contraindicated in children?
Can cause seizures
What is the indication for guaifenesin?
Acute cough, common ingredient in cough medicine
Histamine is released by what cells?
Mast cells and basophils
There are four receptors of histamine, but only two are pharmacologically important. What are those receptors?
H1: smooth muscle cells, endothelium, and brain
H2: gastric mucosa mast cells, immune cells, and brain
What are the general effects of histamine?
- Local vasodilation
- Transudation of fluid through endothelial cells
- Stimulates nerve endings, producing pain and itching
What are the organ-specific effects of histamine?
- Lung- bronchoconstriction
- GI tract contraction and secretion of gastric acid, pepsin, and intrinsic factor
- brain-neurotransmitter
What are the first generation antihistamines?
Diphenhydramine (Benadryl) and Hydroxyzine (Vistaril or Atarax)
What generation of antihistamines should be avoided in the elderly because it may cause delirium, dizziness, or urinary retention?
First generation antihistamines - Diphenhydramine and Hydroxyzine
What are the second generation antihistamines?
Cetirizine
Loratadine
Fexofenadine
What is the MOA of pseudoephedrine?
Sympathomimetric, a and B2-adrenergic receptor agonist
Direct stimulation of alpha-adrenergic receptors of respiratory mucosa causes vasoconstriction and of beta-adrenergic receptors causes bronchial relaxation
What are the indications of pseudoephedrine?
Acute nasal congestion, sinusitis, and otitis media
What is the MOA of phenylephrine?
Binds primarily to alpha-1 receptors, causing vasoconstriction
These two drug classes can increase clearance of phenylephrine making them less effective?
ACE inhibitors and CCBs
Interaction with these drugs can increase the concentration of phenylephrine?
MAOI’s and tricyclic antidepressants
To prevent rebound congestion what is the maximum recommended duration of use for Oxymetazoline (Afrin)?
3 days
What are the indications of inhaled nasal fluticasone?
Treatment and prevention of allergic rhinitis
Chronic nasal polyps
What are the side effects of inhaled nasal fluticasone?
Epitaxis, pharyngitis, systemic absorption of steroid is possible
What are the available inhaled antihistamines?
Azelastine and Olopatadine
Diphenhydramine (Benadryl) and Hydroxyzine are what generation anti-histamines?
1st generation
What are the indications for diphenhydramine (Benadryl)?
Allergic reactions
What is included in the PK for diphenhydramine (Benadryl)?
Oral, acts quickly
Dosed every 6 hours
What are the adverse reactions associated with diphenhydramine (Benadryl)?
Sedation
Avoid in elderly- may cause delerium, dizziness, and urinary retention
What are the indications for Hydroxyzine?
Allergic reactions and can be used as an anxiolytic
What are the adverse reactions associated with hydroxyzine?
Sedation and avoid in elderly (same as diphenhydramine)
What drugs are 2nd generation anti-histamines?
- Cetirizine (Zyrtec)
- Loratadine (Claritin)
- Fexofenadine (Allegra)
What are the adverse reactions of the 2nd generation anti-histamines?
Occasionally sedating
What are the indications of the 2nd generation anti-histamines?
Relieve sneezing, rhinnorhea and nasal itching. Does not reduce congestion.
What is the brand name for Cetirizine?
Zyrtec
What is the brand name for Loratadine?
Claritin
What is the brand name for Fexofenadine?
Allegra
The most commonly associated side effect of nasal decongestants are?
Rebound congestion
