Antihistamines and Drugs for Allergic Rhinitis, Cough, and Colds Flashcards
Can you have an initial allergic response to a first time exposure?
No.
Histamine receptors are lined where?
Lined through the skin, lungs, GI tract with mast cells and basophils.
You will see what with Histamine 1 stimulation?
vasodilation, increased cap. permeability, bronchoconstriction, itching, pain, mucus secretions.
You will see what with Histamine 2 stimulation?
Gastric acid secretion on parietal cells in the stomach
Allergic Rhinitis is seen as what kind of Histamine stimulation?
Histamine 1
Allergic Rhinitis affects what regions of the body?
Upper and lower airways and eyes.
What triggers Allergic Rhinitis?
Seasonal hay fever (outdoor allergens)
Perennial (indoor allergies)
What triggers Allergic Rhinitis to propagate?
Exposure to indoor or outdoor allergen such as IgE antibody simulation where the attach to mast cells and basophils. This then can produce a re-exposure trigger releasing histamines, leukotrienes, and prostaglandins.
Most effective treatment for Allergic Rhinitis?
Intranasal Glucocorticoids preventing an inflammatory response to allergens.
1st generation Intranasal glucocorticoids do what?
increased systemic absorption, used in patients 6 years or OLDER.
2nd generation Intranasal glucocorticoids do what?
Decrease systemic absorption
2nd generation glucocorticoid – Fluticasone propionate used?
4 y/o +
2nd generation glucocorticoid – Fluticasone furoate OR mometasone used?
2 y/o +
What can be used daily for Allergic Rhinitis?
Metered dose sprays - when symptoms are controlled, revert to lowest dose possible
If nasal congestion is present, use what first?
TOPICAL decongestant before intranasal.
Topical decongestants are medications applied directly to the nasal passages to relieve nasal congestion.
Example: VAPOCOOL rub!
What RARE a/e can occur with intranasal glucocorticoids?
Adrenal suppression and slow of linear growth.
Antihistamines has how many generations?
2 generations!
Examples of 1st generation antihistamines?
- Brompheniramine
- Diphenhydramine
- Prometazine
- Hydroxyzine
- Cyproheptadine
Examples of 2nd generation antihistamines?
- Cetirizine (Zyrtec)
- Levocetirizine
- Fexonfenadine (Allegra)
- Lortadine (Claritin)
- Desloratadine (Clarinex)
Difference between 1st generation antihistamines and 2nd generation antihistamines?
1st generation ARE lipid soluble thus it easily crossed into the BBB and causes excessive sedation and drowsiness.
2nd generation are NOT lipid soluble thus not causing any effects.
Antihistamines are taken for what?
Prophylaxis
Take regularly to prevent histamine receptor activation
it DOES NOT reduce nasal congestion
First generation (Diphenhydramine) can be prescribed to who?
Kids under 10kg
What are common a/e for Diphenhydramine in kids?
sedation d/t it being highly lipid soluble – can also produce anticholinergic effects.
Second generation (Loratadine or cetirizine) can be prescribed to who?
6 y/o and older
What is different about Loratadine or Cetirizine in kids?
it CANNOT cross the BBB d/t it being low in lipid solubility thus resulting in little to no sedation
Azelastine can be prescribed to children around what age?
5-11 years old = HALF DOSE
12 years old and older = FULL DOSE
Promethazine is contraindicated in what age group and why?
In children younger than 2 y/o due to severe RDS, needs to be used with EXTREME caution in ALL children
Antihistamines can worsen what in the older generation?
Glaucoma and BPH.
Intranasal Cromolyn (antihistamine) helps with what?
reduces s/sx by suppressing the release of histamine, can be used prophylactically with minimal adverse reactions.
Oral and Intranasal Sympathomimetics MOA?
Activate alpha 1 adrenergic receptors on nasal blood vessels and reduces nasal congestion by shrinking swollen membranes allowing nasal drainage
NASAL Sympathomimetic usage?
Phenylephrine - drops
Oxymetazoline - long acting
RAPID and INTENSE vasoconstriction
ORAL Sympathomimetic usage?
Phenylephrine 4 y/o and up
Pseudophedrine 6 y/o and up
DELAYED response and PROLONGED
What is a common consideration when prescribing sympathomimetics? What are a/e?
DO NOT USE LONGER THAN 5 CONSECUTIVE DAYS
A/e: rebound congestion, CNS stim, CV effects, stroke
Ipratopium Bromide does what?
Is a anticholinergic agent that inhibts secretions of mucus in the nasal mucosa and DOES NOT DECREASE SNEEZING, CONGESTION OR NASAL DRIP!
Montelukast does what?
Leukotriene antagonist that relieves nasal congestion with POSSIBLE neuropsychiatric effects
Omalizumab does what?
Monoclonal antibody directed against IgE and used as OFF LABEL of Allergic Rhinitis.
What two groups are available as antitussive (cough) agents?
Opioid Antitussives & NON-Opioid Antitussive
Opioid Antitussive Agent MOA and Use
Elevate cough thresholds (less coughing) in the CNS
Codeine – MORE effective
Hydrocodone – MORE potent, higher potential for abuse
CAN LEAD TO RDS (opioid)
Should not use Opioid Antitussive Agents in what population?
Kids who have reduced respiratory reserve
NON-Opioid Antitussive MOA and Use
Dextromethorphan – blocks N-methly-D aspartate in the brain
Diphenhydramine – suppresses cough with doses that produce prominent sedation
Benzonatate – decreases sensitivity of respiratory tract stretch receptors
Guaifensin is used for what?
COUGH
renders cough more productive while allowing flow of respiratory tract secretions outwards
Mucolytic agents for cough?
Acetylcysteine – smells like rotten eggs r/t high sulfur content
CAN TRIGGER BRONCHOSPASM
Pediatric OTC Cold Remedies used with CAUTION with which age groups?
AVOID OTC cold remeides in children younger than 6 y/o
