Antimicrobials Flashcards
PCP
- dx
- tx
Dx: CXR (ground glass, interstitial/alveolar infiltrates), LDH >500, Flourescence sputum stain or bronchoalveolar lavage
Tx: TMP-SMX x 21 days
or IV pentamidine
+ Prednisone if PaO2 <70mmHg
Impetigo tx (infxn of epidermis) - GBS
Limited infxn: topical mupirocin
Extensive infxn:
- Staph/strep: Cephalexin or dicloxacillin
- if MRSA concern: TMP-SMX or doxycycline
Erysipelas tx (infxn of upper dermis)
GBS - PCN
S. aureus - cephalexin
MRSA - TMP-SMX or doxycycline
Cellulitis tx (infxn of entire dermis and subQ fat)
Cephalexin
If MRSA - TMP-SMX or doxycycline or clindamycin or Vanc (if inpt)
If human/animal bite: amox/clav (for anaerobes).
Nec Fasc tx
1 cause GAS: PCN, or Pip/taz
Clindamycin - stop toxin production
Vancomycin - MRSA coverage
Pre-septal cellulitis tx
Orbital cellulitis tx
Pre-septal cellulitis (S. aureus, Strep) - cephalexin, dicloxacillin
Orbital cellulitis
- GRNs: CTX, amp/sulbactam
- Skin flora/MRSA: Vancomycin
Osteomyelitis:
- Dx
- Tx
Dx: plain films of area. If nl -> MRI
- If plain films or MRI is abnl -> bone bx w/ culture
Tx: Immediate broad coverage Staph - Nafcillin, oxacillin, cefazolin MRSA - Vanc, Clindamycin GN (salmonella) - CTX Pseudomonas (IVDU, DM, LE ulcers) - Pip/Taz
Septic Arthritis tx
Commonly caused by skin flora - Empiric abx: Vanc ( S. aureus) > Pip/taz, cetazidine or CTX (Unusual pathogens, Kingella, H. influ, N gonorrhea)
DIverticulitis
- dx?
- Tx?
Dx: CT (Do NOT Scope until acute process resolves! Risk of perf)
Tx: Bowel rest + Ciprofloxacin and Metronidazole
Encephalitis
Dx?
Tx
Lumbar puncture -> CSF (HSV PCR and HSV culture)
IV acyclovir
West Nile Encephalitis
- Sx?
- Dx?
Fever + AMS
and Extrapyramidal sx or flaccid paralysis suggestive of transverse myelitis
Serum or CSF IGM antibody to WNV
Supportive tx
Bacterial meningitis tx
Dexamethasone b4 abx if S. pneumo is suspected (lowers mortality)
Neonate: GBS, E. coli, Listeria
- Ampicillin + Aminoglycoside (gentamycin)
- Ceftriaxone can displace albumin-bound bilirubin in neonates, thereby increasing the amount of free bilirubin. The resultant hyperbilirubinemia can cross the blood-brain barrier and increase the risk of KERNICTERUS.
Child/Adult: Strep pneumo, N. meningitidis: CTX + Vanc
Acute sinusitis (Fever, h/a, facial pain/swelling) tx
7-10 d of amox/clav or doxycycline
Otitis media (fever + unilateral ear pain, bulging TM)
<2 y.o: amox/clav for 10 d
2-5 y.o: amox/clav for 7 d
>6 y.o: amox clav 7 d
Otitis externa (foul smelling drainage, tenderness upon pulling pinna) tx
remove foreign material
Minimal sx - topical acidifiers (acetic acid, domeboro)
Moderate sx - topical abx (ofloxacin, neomycin) + steroids
Severe sx (malignant otitis externa): IV Ciprofloxacin - classically caused by pseudomonas
Pharyngitis tx
GAS: PCN (or macrolide if PCN allergy)
Meningococcal prophylaxis for close contacts
( >8 hours of exposure in close proximity (<3 feet) to the affected patient or as direct exposure to respiratory secretions)
Recommended regimens include rifampin (600 mg orally twice daily for 2 days), ciprofloxacin (500 mg single oral dose), and ceftriaxone (250 mg single dose)
*Rifampin would generally be preferred, but it interacts with oral contraceptive pills (OCPs) to decrease their efficacy. Rifampin increases hepatic clearance of OCPs
A pt with a + treponemal antibody absorption test, who has neurologic symptoms (eg, headache, blurred vision) requires _________ to evaluate for neurosyphilis.
a lumbar puncture
- (as the treatment for neurosyphilis is different from that for other stages of illness).
CSF analysis reveals an elevated leukocyte count (>5/mm3) and positive VDRL or fluorescent treponemal antibody absorption (FTA-ABS) testing.
Tx of Syphilis
Primary
Secondary
Early latent (<12 months of infection)
IM Benzathine penicillin G,
- 4 million units
- single dose
Tx of Syphilis
Late latent (>12 months of infection)
Unknown duration
Gummatous/CV syphilis
IM Benzathine penicillin G,
2.4 million units
- weekly
for 3 weeks
Tx of Syphilis
Neurosyphilis
IV Aqueous penicillin G,
3-4 million units
- every 4 hours for 10-14 days
Tx of Congenital syphilis
IV Aqueous penicillin G,
50,000 units/kg/dose
- every 8-12 hours for 10 days
Jarisch-Herxheimer reaction is an acute febrile response that often occurs after the initial treatment of spirochetal illnesses such as syphilis.
- How do you prevent/treat?
No effective prevention is available, but manifestations are generally self-limited and resolve within 48 hours.
condylomata acuminata (anogenital warts),
- due to human papilloma virus infection.
- typically skin-colored or pink and vary in appearance from smooth, flattened papules to verrucous, papilliform growths.
First-line treatment ?
topical imiquimod, an immunomodulatory drug,
