, USMLE Step 2 – High-Yield Antibiotics & Treatments
Overview | 2025 Exam-Focused Infectious Disease &
Pharmacology Notes.
Prophylaxis in HIV based on CD4 count (3 big ones)
CD4 < 200 = ppx for PCP w/ bactrim
CD4 < 100 = ppx for toxo w/ double bactrim
CD4 < 50 = ppx for MAC w/ azithromycin
if cant use bactrim, use dapsone
if G6PD deficiency = use atovaquone
post-exposure prophylaxis following HIV exposure?
Tenofovir and Emtricitabine
Tx for disseminated MAC?
clarithromycin and ethambutol (SE is optic neuritis)
prophylaxis vs actual treatment of toxoplasmosis
ppx is double strength bactim
treatment is pyrimethamine and sulfadiazine for 6wks
antibiotics for bacterial meningitis
Vancomycin and Ceftriaxone
if young or old, give ampicillin to cover for listeria
antibiotics used for crypotoccal meningitis
will be in an AIDS pt w/ CD4<200
IV Amphotericin and FLucytosine
tx for lyme disease?
what about lyme meningitis?
lyme disease = doxycycline
if causes meningitis = Ceftriaxone
antibiotic treatment for cellulitis based on presentation
if walk in to office and not super sick: Cephalexin, Clindamycin, or Bactrim
if septic or inpatient = Vancomycin, linezolid
antibiotic treatment for clostridium perfringens (gas gangrene, crepitus, air in soft tissue on xray)
Overview | 2025 Exam-Focused Infectious Disease &
Pharmacology Notes.
Prophylaxis in HIV based on CD4 count (3 big ones)
CD4 < 200 = ppx for PCP w/ bactrim
CD4 < 100 = ppx for toxo w/ double bactrim
CD4 < 50 = ppx for MAC w/ azithromycin
if cant use bactrim, use dapsone
if G6PD deficiency = use atovaquone
post-exposure prophylaxis following HIV exposure?
Tenofovir and Emtricitabine
Tx for disseminated MAC?
clarithromycin and ethambutol (SE is optic neuritis)
prophylaxis vs actual treatment of toxoplasmosis
ppx is double strength bactim
treatment is pyrimethamine and sulfadiazine for 6wks
antibiotics for bacterial meningitis
Vancomycin and Ceftriaxone
if young or old, give ampicillin to cover for listeria
antibiotics used for crypotoccal meningitis
will be in an AIDS pt w/ CD4<200
IV Amphotericin and FLucytosine
tx for lyme disease?
what about lyme meningitis?
lyme disease = doxycycline
if causes meningitis = Ceftriaxone
antibiotic treatment for cellulitis based on presentation
if walk in to office and not super sick: Cephalexin, Clindamycin, or Bactrim
if septic or inpatient = Vancomycin, linezolid
antibiotic treatment for clostridium perfringens (gas gangrene, crepitus, air in soft tissue on xray)
