Infectious Disease

Question 1

Which cephalosporins are good at covering pelvic inflammatory disease along with doxycycline?

Answer 1

Cefotetan and cefoxitin (2nd gen) with anaerobic and some more gram negative coverage

Question 2

3rd generation: ceftriaxone and cefotaxime. compare and contrast

Answer 2

both can cross BBB so good against CNS infections

• ceftriaxone is first line for pneumococcus
• cefotaxime is only better than ceftriaxone in neonates bc neonates have poor glucuronidation activity which ceftriaxone requires but not cefotaxime; similiarly cefotaxime is DOC for SBP

Question 3

Which cephalosporin has anti-pseudomonal coverage

Answer 3

ceftazidime

Question 4

Cefoxitin and cefotetan both 2nd gen is assoc with increased risk of bleeding, why?

Answer 4

deplete prothrombin (PT)

Question 5

Carbapenems (imipenem, meropenem, ertapenem, doripenem) have anti-pseudomonal coverage except which one

Answer 5

ertapenem

Question 6

name the monobactam that is exclusively for gram negative with pseudomonal coverage and has no cross rxns with penicillin

Answer 6

aztreonam

Question 7

Fluoroquinolones should be avoided in children and pregnant ppl b/c?

Answer 7

bone growth abnormalities

Question 8

Which class of abx is assoc with tendonitis and achilles tendon rupture

Answer 8

fluoroquinolones by inhibiting osteoblast/osteoclasts

Question 9

Fluoroquinolone has great gram neg coverage and can be used for diverticulitis and GI infections. Most require metronidazole to cover anaerobes as well. Which fluoroquinolone has its own anaerobic activity?

Answer 9

moxifloxacin can be given as a single agent with metronidazole in diverticulitis and GI infections

Question 10

Aminoglycosides are nephrotoxic and ototoxic. They have gram neg activity and synergistic with beta lactam ab for some gram positive. Any anaerobic coverage?

Answer 10

NO b/c require O2 to function

Question 11

Penicillin is the DOC for syphillis. What if the pt is allergic?

Answer 11

Aminoglycosides are 2nd choice

***only desensitize to penicillin in someone whos allergic if the someone has CNS syphilis or is pregnant.

Question 12

Doxycycline is good for Lyme disease limited to rash, joint, or CNVII palsy. What’s the abx if pt has CNS and heart symptoms?

Answer 12

ceftriaxone

Question 13

DOC for pregnant ladies with UTI

Answer 13

nitrofurantoin

Question 14

List 4 side effects of doxycycline

Answer 14

• tooth discoloration (children)
• Fanconi syndrome (type II RTA)
• photosensitivity
• esophagitis/ulcer

Question 15

ABX that can cover MRSA

Answer 15

• vancomycin
• linezolid (side effect: plt inhibition)
• daptomycin (side effect: increase CK; not good for lung infections b/c pH inactivates it)
• tigecycline
• ceftaroline
• tmp/smx
• clindamycin
• doxycycline

Question 16

Gram negative bacilli (e. coli, klebsiella, proteus, pseudomonas, enterobacter, citrobacter) cause infections of the bowel (peritonitis, diverticulitis), UTI and liver (cholecystitis, cholangitis). List the 6 groups of abx that cover GRAM-NEGATIVE bacilli

Answer 16

• quinolones
• aminoglycosides
• carbapenems
• piperacillin, ticarcillin
• aztreonams
• cephalosporins

Question 17

How to treat bacterial meningitis?

Answer 17

ceftriaxone, vancomycin, dexamethasone

dependent on CSF cell count as cx take time to come back

Question 18

Which meningitis is assoc with the highest level of CSF protein?

Answer 18

TB meningitis (glucose can be low too)

Question 19

Most common cause of bacterial meningitis in adults vs neonates

Answer 19

adults - s. pneumo

neonates - Group B strep

Question 20

Fever, headache neck stiffness + AIDS with CD4 cells

Answer 20

cryptococcal meningitis (usu slow, several wks of symptoms)
best initial: india ink stain
most accurate: cryptococcal antigen

Question 21

Fever, headache neck stiffness + camper/hiker, rash shaped like a target, joint pain, facial nerve palsy and tick bike

Answer 21

Lyme disease (CNS) so treat with ceftriaxone

Question 22

Fever, headache neck stiffness + camper/hiker, rash that moves from extremities to trunk, tick bite

Answer 22

Rickettsia so treat with doxycycline even in children

Question 23

Fever, headache neck stiffness in adolescent with petechial rash

Answer 23

neisseria meningitidis
pt will need resp isolation
give ppx to close contacts: can give rifampin, cipro or ceftriaxone

Question 24

Which bacteria is assoc with meningitis after neurosurgery

Answer 24

staph aureus

Question 25

LP is best initial and most accurate test for meningitis. When do you do CT of head before LP?

Answer 25

When there are signs of increased ICP or possibility of a space occupying lesion that may cause herniation during LP. When pt has papilledema, seizures, focal neurologic abnormalities, confusion.

Question 26

If there's contraindication to immediate LP in someone with meningitis, do what first then?

Answer 26

treat with abx b/c without treatment can lead to permanent brain damage. Then do CT before LP

Question 27

Most accurate test for TB meningitis

Answer 27

-requires 3 high volume LPs to do acid fast stain and cultures

Question 28

Most accurate test for lyme and ricketssia meningitis

Answer 28

serologic testing, ELISA, western blot, PCR

Question 29

Best initial treatment for bacterial meningitis are ceftriaxone, vancomycin and dexamethasone. When do you add ampicillin.

Answer 29

When you suspect listeria as well esp in ppl at high risk like the elderly, immunocompromised (AIDS/HIV, steroids use, cancer), neonates, pregnant, alcoholics.

Question 30

acute onset of fever and confusion --> encephalitis --> most common cause? What should be done initially? What's most accurate test? How to treat?

Answer 30

most common cause of acute encephalitis herpes simplex. Do head CT first due to presence of confusion. Most accurate test is PCR. Treatment is IV acyclovir (thymidine kinase inhibitor)

Question 31

When do you use iv foscarnet over iv acyclovir (the #1 choice) for herpes encephalitis?

Answer 31

acyclovir-resistant herpes

Question 32

If someone on IV acyclovir has renal toxicity, what should you do? Should you switch to foscarnet?

Answer 32

decrease dose but continue with iv acyclovir with some hydration. DO NOT switch to foscarnet as foscarnet is even more renally toxic.

Question 33

How does acyclovir cause renal toxcitiy

Answer 33

crystal-induced nephropathy as it precipitates in the renal tubules and can cause renal tubule obstruction

Question 34

What is the most common neurologic deficit of untreated bacterial meningitis?

Answer 34

CNVIII

Question 35

Strep pharyngitis can be treated first-line with penicillin or amoxicillin. If allergic to penicillin, give?

Answer 35

if allergy is just a rash, can try cephalexin (1st gen) | if allergy is anaphylaxis, can try clindamycin or macrolide

Question 36

Flu can be treated if presented in less than 48 hours of symptoms can be given neuramindase inhibitors, such as

Answer 36

oseltamivir | zanamivir