HENT Flashcards
Drug groups for HENT?
- Decongestants
- Topical nasal steroids
- Antihistamines
- Anti-tussives
- Expectorants
- Mast cell stabalizers
- Ipratropium
- Leukotriene inhibitors
What is the MOA of decongestants?
alpha-agonists: stimulate a 1 receptors in nasal mucosa to produce vasoconstriction
Decreased blood flow = decreases edema = decreased congestion = increase air flow
Are decongestants used topically or orally?
Both; some orals are Rx
Effects of decongestants?
- shrinks swollen nasal mucosa
- reduces nasal congestion
- increases sinus drainage
- easier to breathe
5 topical decongestants?
- Oxymetazoline (Afrin)
- xylometazoline (otrivin)
- phenylephrine (neo-synephrine)
- naphazoline (privine)
- Tertrahydrozoline (tyzine)
What does pharmacokinetics mean?
What the body does to drug, how it moves through the body
What does pharmacodynamics mean?
what the drug does to the body
Benefits of topical decongestants?
Most effective.
Allows more drug to get where it is needed with less systemic absorption and fewer S/E.
Lasts longer.
How do you use topical nasal decongestants?
1-2 sprays q12
What should you educate your patient on concerning decongestants?
- keep applicator clean
- spray and breathe in
- don’t let it drip down back of throat
- contraindication to using PO decongestants= contraindication to using nasal decongestants
Local and systemic S/E of topical decongestants?
Local:
- stinging
- burning
- dryness of mucous membranes in the nose
- rhinitis medicamentosa
Systemic:
- increased BP
- increased blood sugar
- increased IOP
- chest pain
- difficulty urinating
What is rhinitis medicamentosa? When does it become a problem?
rebound congestion from using topical decongestants >3-5 days and than stopping them
rebound congestion often worse than to begin with
how do you treat rhinitis medicamentosa?
- oral decongestants
- nasal corticosteroids
What are 6 contraindications for topical decongestants? Why?
- CAD (increases rate & work of heart… increases ischemia)
- HTN: increases BP
- hyperthyroidism: worsens
- DM: increase BS
- narrow angle glaucoma: increased IOP could acutely close angle in eye
- BPH: urinary retention
Why are oral decongestants a useful alternative for nasal decongestants? Why aren’t they?
can be used for a longer period of time
no rebound effect
more S/E
Oral decongestant on the market?
- pseudoephedrine
- phenylephrine
What receptors do oral decongestants target?
A1
What oral decongestant also stimulates beta receptors? What additional side effects are seen with it?
pseudoephedrine: tachycardia, increased BP, insomnia (CNS stimulation)
What are the S/E of oral decongestants?
- CNS stimulation
- HTN (risk of stroke small at therapeutic dose)
- Palpitations
When shouldn’t you give an oral decongestant?
- pt with stroke in past
- pt with HTN
What is the MOA of nasal corticosteroids?
- suppress inflammation of nasal passages
- decrease intracellular edema
- decrease nasal discharge
How long do you need to use nasal corticosteroids for?
2-3 weeks; hormones take longer to work
Name 7 topical nasal steroids.
- fluticasone
- beclomethasone
- triamcinolone
- budesonide
- mometasone
- ciclesonide
- flunisolide
What is the common suffixes for nasal steroids?
- asone
- olone
- onide
- olide
What is the common suffix for decongestants?
- zoline
- rine
What is the normal dose of topical nasal steroids?
1-2 sprays in each nostrils twice a day
What should you test for before giving nasal steroids?
nasal patency; normal saline for no potency before steroid (temporarily reduces edema)
What should you remind the pt about not doing for up to 10 minutes after administering a nasal steroid?
sneezing or blowing nose
what are the S/E of topical nasal steroids?
local:
- stinging
- HA
- nose bleeds (from dry membranes)
systemic:
- mild growth suppression in children
how can you reduce nose bleeds with topical nasal steroids? what should you do if one develops?
point drug away from septum; consider stopping medication
List 3 contraindications related to poor wound healing for topical nasal steroids.
- ulceration of nasal septum
- recent nose surgery
- trauma
What are the functions of histamines?
- involvement in immediate allergic & inflammatory rxns
- gastric acid secretion
- CNS: stimulates nerves for pain, itch, sleepiness, cholinergic receptors
- H1 (vasodilation=heat, redness, inflammation)
What are the two type of histamine receptors? Where are they located?
H1: smooth muscle, endothelium, brain
H2: gastric mucosa
When do you use H1 blockers?
allergic conditions (to decrease itch and inflammatory response)
When do you use H2 blockers?
to reduce gastric acid secretions
what is the differences between generation 1 and 2 H1 antagonists?
Generation 1:
- stronger sedative effect
- stronger anticholinergic effect
- better at getting into CNS
Generation 2:
- don’t get into CNS as well
- less sedating
- less anticholinergic effects
List 10 generation 1 anti-histamines.
- diphenhydramine
- chlorpheneramine
- brompheneramine
- clemastine
- azaelastine
- meclizine
- dimenhydrinate
- doxepin
- hydroxyzine
- promethazine
What are other class names for generation 1 anti-histamines?
non-selective antihistamines or sedating antihistamines
what are common suffixes for generation 1 antihistamines?
- zine
- pin
- hydrinate
- stine
- amine
what are common suffixes for generation 2 antihistamines?
- zine
- adine
- idine
- izine
What are other class names for generation 2 antihistamines?
peripherally selective (not affecting CNS) or non sedating antihistamines
Explain the pharmacokinetic antihistamines.
G1&2 rapidly and well absorbed orally
widely distributed throughout body (G2 doesn’t reach CNS)
How long do G1 and G2 drugs work for?
G1: 4-6 hours
G2: 12-24 hours
Explain the pharmacodynamics of antihistamines.
Inhibit activation of H1 by receptors by histamine by binding receptor
easier to prevent effects than to reverse effects of histamine
have other effects on other receptors (muscarinic, alpha, serotonin) because similar in structure to other drugs
What are the effects of anti-histamines?
used in allergies & inflammatory conditions to block effects of histamine release
- sedation (mainly G1)
- anti-nausea
- anti-dizziness
- anticholinergic
These can be useful or S/E (desired or no desired effects).
Do not effect everyone the same (children can get excited not sedated from G1)
where can nausea and vomiting stimulation originate?
- ear (vestibular system)
- CNS
where can dizziness (disequilibrium) originate?
- ear (vestibular system)
- many other causes
What generation is best for reducing nausea and dizziness?
G1
What cause of vomiting and nausea is treated well with anti-histamines? What is a good example of a G1 drug for nausea? vomiting?
vestibular dysfunction (motion sickness)
nausea: meclizine
vomiting: promethazine
What are the anticholinergic effects of anti-histamines?
block muscarinic receptors and causes:
- urinary retention
- blurry vision
- drying effects (decreased nasal, salivary, lacrimal gland secretions)
more common with G1s: dimenhydrinate, diphenhydramine, and promethazine
What do we use H1 antagonists for?
- allergic rhinitis
- pruritis (w/ urticaria and eczema)
- vertigo/motion sickness
what type of allergic rxn is allergic rhinitis? what is it’s MOA? drug of choice?
hypersensitivity; histamine released locally in nasal passages; use antihistamines
how do antihistamines decrease pruritus?
by sedation and making individual less aware of itchiness
how do antihistamines decrease vertigo/motionsickness?
block effect of histamines in inner ear or CNS
What are the S/E (toxicities) of anti-histamines?
- sedation (>G1)
- hallucinations(>G1)
- ataxia (>G1)
- dry mouth (M)
- constipation (M)
- difficulty voiding (M)
- excitation in kids
What are examples of topical nasal antihistamines?
- azelastine (nasal)
- ketotifen (gtt)
How often is azelastine given? what are the S/E
2 sprays in each nostril BID; S/E= HA, dryness, bitter taste, drowsiness; decreased effectiveness over time
how often is ketotifen given?
1 ggt OU BID
What are anti-tussive used for? how do they work?
decreasing cough by decreasing cough reflex in throat and brain
When should you not use anti-tussives?
productive cough (unless it has advanced to inducing other negative effects - like interfering with sleep)
Name two oral antitussives.
Dextromethorphan and narcotics
what is the advantage of dextromethorphan?
OTC and no drowsiness
Most common narcotic used for cough? Dose? Others?
1: codeine, 10mg
- phenergan with codeine
- robitussin AC
- Tussionex
How do narcotics work to suppress a cough?
suppress cough reflex in the throat and brain (centrally & peripherally working)
What are the active ingredients in topical antitussives?
- camphor
- menthol
how are topical antitussives used?
- rubbed on throat or chest and inhaled
- lozengers
- throat sprays
what is the MOA of topical antitussives?
stimulate cold sensory receptors and give sensation of cooling and local anesthetic effect to decrease cough
How do expectorants work?
help to bring up secretions
what is an example of an expectorant?
guaifenesin (mucinex, mucinex DM, mucinex D)
what is the MOA of expectorants?
stimulate secretions of respiratory tract (including throat), increasing volume of secretions
makes secretions thinner and easier to cough up
When are expectorants used?
with a productive cough, they have to bring phlegm up more easily
what should be taken with expectorants?
8 oz water
S/E of expectorants?
Few and mild
What is another term for expectorant?
mucolytics
What is an example of a mast cell stabilizer?
cromolyn sodium
how do mast cell stabilizers work?
stabilize mast cells so there is no degranulation or release of histamine
what are mast cell stabilizers best used for?
preventing allergic rhinitis symptoms (little effect after mast cells release histamine)
How is cromolyn sodium delivered?
topically; nasal spray
ADRs and disadvantages of cromolyn sodium/mast cell stabilizers?
- nasal stinging
- sneezing
- takes 1-2 weeks to work
- have to take 3-4 qD
what is the drug of choice for sneezing and rhinorrhea from pregnancy? why?
cromolyn sodium (mast cell stabliizer) because it is not absorbed and poses no risk to fetus
what cholinergic blockers are used in HENT?
ipratropium nasal spray
MOA of ipratropium (cholinergic blocker)?
antagonist to cholinergic receptors in nasal passage
inhibits secretions from serous and seromucous glands in nasal mucosa
Indications for ipratropium?
runny nose
S/E of ipratropium?
- HA
- Dry nose
- Nose bleeds
What are examples of leukotriene inhibitors used for HENT?
- montelukast
- zarfirlukast
what is the delivery method for leukotrienes inhibitors?
oral
what is the MOA for leukotriene inhibitors?
leukotrienes are released in response to allergic reactions; these drugs decrease response in allergic/hypersensitivity rxns
what are leukotriene inhibitors indicated for?
- ear, nose, throat diseases
- allergic rhinitis
- seasonal rhinitis
what is the first line for allergic rhinitis?
- antihistamines (help with sneezing, runny nose, itching, and conjunctivitis)
- decongestants
- nasal corticosteroids
What is the second line for allergic rhinitis?
- ipratropium (rhinorrhea)
- anti-tussive (dry cough)
- expectorant (wet cough)
what should you do if you choose a antihistamine for allergic rhinitis and it doesn’t work? what should you do if it stops working?
start a chemically different antihistamine
Commercially available preparations combine different drugs (ex. decongestant + antihistamine + antitussive); is this always beneficial?
No, pt may not need all of these drugs, start one drug and add another group if needed
what medications are effective for colds (URI or viral rhinitis)?
- decongestands
- antipyretics
Possibly antitussives, nasal steroids, or ipratropium
what does not help colds (URIs or viral rhinitis) or bacterial sinusitis?
anti-histamines
don’t help and possible slow down improvement
How do we treat sinusitis? what is the problem with treating sinusitis?
may have bacterial infection can accompany the infection
can also use:
- nasal steroids
- antibiotics
- decongestants
when is the only time antihistamines should be used with sinusitis?
if the pt has allergic rhinitis too
generation 2 antihistamines?
- cetirizine
- fexofenadine
- loratidine
- desloratidine
- levalcetirizine
