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67 Cards in this Set

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3 most common causative organisms in ABRS.
S. pneumoniae (20-43%)
H. influenzae (22-35%)
M. catarrhalis (2-10%)
Possible sequelae of failed antibiotic therapy in immunocompromised patients:
Orbital cellulitis
Meningitis
Septicemia
About S. pneumoniae
Gram positive diplococcus.
Most common cause of ABRS, CAP and AOM.
About H. influenzae
Gram negative bacillus.
Commonly causes ABRS, CAP, and AOM.
What factors favor H. influenzae as the causative agent?
Tobacco use.
Recurrent infection.
About M. catarrhalis.
Gram negative coccus
Significantly less frequent cause of ABRS, CAP and AOM.
Mechanism of resistance to penicillin of S. pneumo.
Altered binding sites. This can be overcome by increasing drug concentration.
Percent penicillin resistance of S. pneumo.
25%
Risk factors for DRSP.
Antimicrobial use within 4-6 weeks.
Exposure to child in day care.
Elderly.
Percent penicillin resistance of H. influenzae.
30%
Percent penicillin resistance of M. catarrhalis.
90%
Mechanism of penicillin resistance of M. cat and H. inf
Beta lactamase. This is overcome by adding clavulanate to amoxicillin or using a non-penicillin class drug.
Expected course of a viral URI.
Some improvement by day 5. Lingering cough at day 7 is normal.
When does viral replication peak in a URI?
Day 2-3.
Timing of symptoms that suggests bacterial etiology.
Symptoms lasting > 7-10 days or worsening after 5-7 days.
What is considered antimicrobial treatment failure?
No improvement after 72 hours. Be sure to question about adherence.
What organisms does amoxicillin treat?
At 1.5 g/d, only susceptible organisms.

At 4.0 g/d, some DRSP and susceptible gram-negatives.

Does NOT treat beta-lactamase producing gram-negatives.
What organisms does amoxicillin/clavulanate treat?
At low dose this covers beta-lactamase producing gram negatives but not DRSP.

At high dose, it covers DRSP and resistant gram-negatives.
Which cephalosporins are recommended for ABRS?
cefpodoxime (Vantin) - 3rd gen
cefuroxime axetil (Ceftin) - 2nd gen
cefdinir (Omnicef) - 3rd gen
What organisms do the cephalosporins for ABRS treat?
Gram positives.

beta-lactamase producing gram negatives.
What is the main factor that limits amoxicillin/clavulanate use?
It causes significant GI upset. Counsel patients to take medication with food, especially fatty foods.
What drugs are options for penicillin-allergic patients with mild disease and no antibiotic use in the last 4-6 weeks?
TMP/SMX

Doxycycline

a macrolide
First-line therapy for moderate ABRS or abx use in the last 4-6 weeks.

Alternates.
High dose amoxicillin/clavulanate (4 g/day).

Respiratory fluroquinolone

Clindamycin + rifampin

Ceftriaxone IM
Can patients with penicillin allergy take cephalosporins?
No.
Are cephalosporins stable in the presence of beta lactamase?
Yes.
What are the respiratory fluroquinolones?
moxifloxacin
levofloxacin
Why is clindamycin + rifampin not a preferred treatment?
clindamycin has a high risk for GI side effects including C. diff colitis.
Clindamycin is included in the drug regimen to cover:
DRSP.
What organisms are covered by respiratory fluroquinolones?
DRSP and beta-lactamase producing gram-negatives.
Best drug choice for a 25 year old college student with mild disease.
low dose amoxicillin eg. 875 mg bid.
Best ABRS drug choice for a 35 year old mother of a 3 year old in daycare with no recent antibiotic use.
High dose amoxicillin (4 g daily)
Best ABRS drug choice for a 50 year old male who was prescribed amoxicillin for sinusitis 4 weeks ago.
HD amoxicillin/clavulanate
Best ABRS drug choice for a very sick patient who is allergic to penicillin.
respiratory fluroquinolone
Best ABRS drug choice for a middle-aged man with uncertain medication history who is allergic to penicillin.
a) clarithromycin
b) azithromycin
c) amoxicillin
d) cefdinir
b) azithromycin.

Clarithromycin is a CYP inhibitor and should be avoided if drug interactions cannot be managed.
Which of the macrolides is NOT a CYP inhibitor?
azithromycin
Possible consequence of concomitant clarithromycin and atorvastatin use:
Rhabdomyolysis from increased atorvastatin (CYP substrate) levels.
Marked eyelid edema in the context of ABRS is suggestive of
Extension of infection beyond the sinuses to periorbital cellulitis.
Best ABRS drug choice for a 45 year old with 35 pack-year smoking history.
Amoxicillin/clavulanate.
When is CT of the sinuses indicated in w/u of ABRS?
Only if there is treatment failure after escalating to strong therapy such as fluroquinolones or clindamycin + rifampin.

Not recommended for initial diagnosis.
What is the most important component of allergic rhinitis/conjunctivitis therapy?
Allergen avoidance.
During what time of the day is the allergen concentration highest?
In the morning, as pollen is released at night.
Mechanism of action of decongestants:
Vasoconstriction.
Oral decongestants are contraindicated in these patients.
Patients with CV disease or uncontrolled HTN.
Why are first-generation antihistamines more sedating than second-generation?
They penetrate the blood-brain barrier better.
What classes of allergic rhinitis drugs are recommended for use as controller therapy?
Nasal corticosteroid spray (most potent, as it works on the most inflammatory mediators)

Leukotriene modifiers.

Mast cell stabilizers.
Name the leukotriene modifier medications used in allergic rhinitis.
montelukast (Singluair) PO

zafirlukast (Accolate) PO
Name the mast cell stabilizers used in allergic rhinitis.
cromolyn (NasalCrom intranasal and Opticrom optic). These are OTC.

nedocromil (Alocril optic) Rx.

Note that inhaled cromolyn (Intal) is approved for asthma, NOT allergic rhinitis.
What is one limitation of allergic rhinitis controller therapy?
It requires 1-4 weeks to become effective.
Name two first-generation antihistamines.
diphenhydramine (Benadryl)
chlorpheniramine (Chlor-Trimeton)
Are first or second generation antihistamines more effective as rescue therapy for allergic rhinitis?
First generation antihistamines are more effective but also more sedating.
Name 5 second generation antihistamines.
loratadine (Claritin)
desloratadine (Clarinex)
cetirizine (Zyrtec)
fexofenadine (Allegra)
levocetirazine (Xyzal)
Name the classes of drugs used in allergic rhinitis for PO rescue therapy aimed at deactivating formed inflammatory mediators.
1st and 2nd generation antihistamines.
Name classes of drugs used in allergic rhinitis for symptom relief targeted at profuse nasal discharge.
Anticholinergic nasal spray

Antihistamine nasal spray
Name classes of drugs used in allergic rhinitis for symptom relief targeted at nasal congestion.
Oral decongestants

Nasal decongestants
Name an anticholinergic nasal spray.
Ipratropium nasal (Atrovent nasal)

Note ipratropium inhaled (Atrovent HFA) is approved for COPD and asthma, NOT allergic rhinitis.
Name an antihistamine nasal spray.
azelastine hydrochloride (Astelin, Astepro)
Name an antihistamine for opthalmic use.
olopatadine hydrocholride (Patanol)
Name two nasal decongestants.
phenylephrine (Neo-Synephrine and other trade names)

oxymetazoline (Afrin, Dristan, other trade names)
Some information about Afrin.
Afrin is a nasal decongestent/vasoconstrictor with generic name oxymetazoline. It can be used safely for up to 10 days, but may cause rebound stuffiness.
Name two oral decongestants.
pseudoephedrine (Sudafed)

phenylephrine (Sudafed PE)
Anticholinergic drugs should be avoided in this population, if possible.
Elders.
Mnemonic for anticholinergic side effects.
Dry as a bone (dry mouth)
Red as a beet (flushing)
Mad as a hatter (confusion)
Hot as a hare (hyperthermia)
Can's see (mydriasis/blurred vision)
Can't pee (urinary retention)
Can't spit (dry mouth)
Can't shit (constipation)
When is urinary retention from anticholinergic use most concerning?
In elderly male patients with BPH. It rarely occurs in younger patients.
About agitation secondary to anticholinergic medications.
Agitation occurs in 10% of the population. It is an atypical side effect, as 90% will experience sedation.
Mechanism of action of decongestants.
They are vasoconstrictors and alpha-adrenergic agonists.
Therapeutic effect of anticholinergic nasal spray.
Dries secretions.
Safety considerations in prescribing antihistamine rescue therapy for allergic rhinitis.
First generation antihistamines should be used only when there is no risk from sedation ie. not driving or operating machinery.