USMLE Step 3 Latest Update 2024-2025 300
Questions and 100% Verified Correct Answers
Actual Exam Guaranteed A+
5 causes of microcytic anemia - CORRECT ANSWER: iron deficiency, lead poisoning,
anemia of chronic disease (but usually normocytic), thalassemia, sideroblastic anemia
(can also have high MCV)
Abx safe in pregnancy - CORRECT ANSWER: -PCNs
-cephalosporins
-aztreonam
-erythromycin
-azithromycin
Abx with NO anaerobic coverage - CORRECT ANSWER: aminoglycs, aztreonam,
fluoroquinolones, oxacillin/nafcillin, all cephalosporins EXCEPT cefoxitin and cefotetan
Acanthocytes on blood smear (looks like spur cell but with more rounded spurs) -
CORRECT ANSWER: liver disease, hypothyroidism, alcoholism
Achalasia - CORRECT ANSWER: -high tone LES
-bird's beak on barium swallow
-histology shows hypertrophied inner circular muscle with absence of ganglia of
Auerbach's plexus
-tx with balloon dilation or surgery
Actinomyces - CORRECT ANSWER: -normal immune system w/ facial or dental trauma
-dx with gram stain and confirm with anaerobic cx
-branching, filamentous bacteria (LIKE nocardia!)
,-tx with PCN
Adequacy of sputum sample - CORRECT ANSWER: <10 squamous cells and >25 leuks
per LPF
Adjustment of levothyroxine in pregnancy - CORRECT ANSWER: -INCREASE dose as
soon as pregnancy is confirmed
-most pt.s require increase of 25-50%
-check TSH once a trimester
-checking T3 and T4 not effective b/c these levels are increased during pregnancy due
to increased thyroid-binding globulin
Adverse effects of NNRTIs - CORRECT ANSWER: ??
efavirenz
nevirapine
Adverse effects of NRTIs - CORRECT ANSWER: lactic acidosis
zidovudine: anemia
didanosine: pancreatitis and peripheral neuropathy
stavudine: pancreatitis and neuropathy
lamivudine: none
abacavir: rash
emtricitabine: none
Adverse effects of protease inhibitors - CORRECT ANSWER: hyperglycemia
hyperlipidemia
,indinavir: kidney stones
ritonavir
lopinavir
nelfinavir
saquinavir
darunavir
tipranavir
amprenavir
atazanavir
Aeromonas hydrophila - CORRECT ANSWER: This gram-negative bacterium is found
in freshwater environments, although it may also be present in brackish water.
Infections are more likely to occur during warmer weather. Soft tissue involvement and
bacteremia/sepsis can develop in patients with underlying immunocompromising
diseases, including cirrhosis and cancer. The clinical presentations of infection with
Vibrio vulnificus and Aeromonas species can be quite similar. This organism is often
susceptible to fluoroquinolones, trimethoprim-sulfamethoxazole, tetracyclines,
imipenem, aminoglycosides, and third- or fourth-generation cephalosporins
Alcoholic ketoacidosis - CORRECT ANSWER: -AG acidosis
-increased osmolal gap
-ketonemia or ketonuria
-variable blood glucose level, but if higher than 250 think DKA
-tx with IVF (D5NS) and thiamine
Alcoholic with PNA - CORRECT ANSWER: strep pneumo, oral anaerobes, Klebsiella
pneumo, Acinetobacter, M. tuberculosis
Anaerobes - CORRECT ANSWER: -metronidazole is BEST for abdominal anaerobes
(carbapenems, piperacillin, and ticarcillin have equal efficacy)
-cefoxitin and cefotetan are the ONLY cephalosporins
, -respiratory anaerobes: clindamycin
Antibiotics for GNRs - CORRECT ANSWER: Cephalosporins: cefepime, ceftazidime
PCNs: piperacillin, ticaricillin
Monobactam: Aztreonam
Quinolones: cipro, levo, gati, moxi
Aminoglycs: gentamicin, tobramycin, amikacin
Carbapenems: imipenem, mero, erta
Antibiotics for MRSA - CORRECT ANSWER: IV: vanc, linezolid, daptomycin,
tigecycline;
if minor infection, can use oral: TMP/SMX, doxy, minocycline, or maybe clindamycin
(there is inducible resistance to clinda though)
Antibiotics for MSSA - CORRECT ANSWER: Oxacillin/nafcillin, dicloxacillin (IV and
oral), cefazolin (IV), cephalexin (oral)
Antibiotics for strep - CORRECT ANSWER: PCN, ampicillin, amoxicillin
Antibiotics to use for Staph with PCN allergy - CORRECT ANSWER: cephalosporins if
rash only; macrolides, clindamycin, vancomycin, linezolid, daptomycin, TMP/SMX
Antibody test for celiac disease - CORRECT ANSWER: anti-endomysial, tissue
transglutaminase (small bowel bx is best though)
Aspiration PNA - CORRECT ANSWER: gram negative enterics, oral anaerobes
Asymptomatic bacteriuria - CORRECT ANSWER: only treat in pregnant women
Babesiosis - CORRECT ANSWER: -causes hemolytic anemia