Antibiotic Review Flashcards
What is on your differential for pharyngitis?
Bacteria: Group A or C Streptococcus, Corynebacterium diphtheriae, Haemophilus influenzae
Yeast/Fungal: Candida
Virus: Coronavirus, Influenza, Rhinovirus, EBV, Coxsackie, Acute HIV
–> GERD (older adults)
What are the Modified Centor Criteria for Pharyngitis and Tonsillitis? (diagnosing strep. infection)
- Absence of cough - 1
- Age 3 -14 yrs - 1
- Age 15-45 yrs - 0
- Age older than 45 yrs - -1
- Anterior cervical lymphadenopathy - 1
- Fever - 1
- Tonsillar erythema or exudates - 1
What does low sensitivity indicate?
People will have the disease and not test positive.
What might the low sensitivity of the rapid antigen detection strep test indicate?
- May be due to variability in C-carbohydrate that the test looks for
- You may not have had enough of the organism on the swab for it to test positive
What does Streptococcus pyogenes look like on gram stain?
Gram (+) - Purple cocci in chains
What can Ampicillin cause in Streptococcus pyogenes patients?
It can cause a rash which can incorrectly label the individual as having a penicillin allergy
What are the three best treatments for patients with a Group A Streptococcal Infection?
- Penicillin V
- Amoxicillin
- Penicillin G
What effect does EPI have on a patient’s vascular system?
Vasoconstricts
What adrenoceptor primarily mediates the vascular response?
Alpha1 (via PLC)
What effect does EPI have on the respiratory system?
Bronchodilates
Which adrenoreceptor primarily mediates the respiratory system?
Beta2
What can you do to check for penicillin allergy?
Skin test, if positive it indicates the presence of IgE antibodies to penicillin and excludes the use of other beta lactam antibiotics including cephalosporins
What is Aztreonam?
A monobactam that is safe to use in patients with penicillin allergies
-Not a good choice for Streptococcus pharyngitis bc Azteonam is effective against gram - only
What groups are bacteriostatic antibiotics not advisable to use?
Immunocompromised or life-threatening acute infections
What can penicillin allergy result in treatment with?
Inferior drugs (non-bactericidal drugs)
What does H. influenzae secrete that can impact Strep. pyogenes treatment?
Beta-lactamases!!
What patients have bacteremia and should be started on IV antibiotics?
Pts. with rigors, shakes, chills, high fever, night sweats
What is antigenic shift?
Gene reassortment leading to altered surface proteins and antigenic profile.
-Create new subtypes
What is antigenic drift?
Small gene mutations/changes leading to altered antibody-binding sites and escape from immunity.
What is the most common cause of infection-related mortality in the US?
Influenza + Secondary Bacterial Pneumonia
What about an influenza infection enhances bacterial growth?
- Apoptosis of airway epithelial cells
- Inhibition of mucocilliary clearance
- Viral neuramidase
What is pre-emptive treatment?
Treatment of patients who have clinical, imagining or other testing that provides evidence of disease
What is the first line empiric treatment for Community Acquired Pneumonia in previously healthy patients without past antibiotic use?
- Macrolide
- Doxycycline
How should you treat outpatients with comorbidities or antibiotic use in the past three months with CAP?
- Resp. fluoroquinolone (Levofloxacin, gemifloxacin, moxifloxacin)
- Beta-lactam antibiotic (amoxicillin, augmentin, cefpodoxime)
- -> Plus Macrolide
