ID II: Bacterial Infections

Question 1

drug of choice for perioperative orthopedic ABX ppx

Answer 1

cefazolin (covers skin flora staph and strep, MSSA)
start within 60 min prior to procedure

Question 2

drug of choice for perioperative cardiac or vascular ABX ppx

Answer 2

cefazolin start 60 min pre op
or
cefuroxime (more G- coverage)

Question 3

drug of choice for perioperative GI ABX ppx

Answer 3

cefazolin + metronidazole
or
cefotetan, cefoxitin
or
amp/sul

Question 4

meningitis in <1 month old
likely pathogens
treatment

Answer 4

listeria = #1
neisseria meningitidis
h inf
s pneumo
ampicillin + cefotaxime or gentamicin

NO CTX IN NEONATES 2/2 biliary sludging

Question 5

meningitis in 1 month to 50 yo
likely pathogens
treatment

Answer 5

s pneumo
n meningitidis
h inf
need double strep coverage!!

CTX or cefotaxime
+
vanco

Question 6

meningitis in >50 yo
likely pathogens
treatment

Answer 6

listeria = #1
n menin
h inf
s pneumo

need to cover listeria and double strep coverage

amp
+
CTX or cefotaxime
+
vanco

Question 7

AOM
what classifies as non severe?
what classifies as severe?
treatment for each?
duration of treatment?

Answer 7

non-severe = otalgia <48h, no otorrhea, T <102.2 (39C) –> observe for 2-3d, supportive care
severe = otorrhea, T >102.2, LESS THAN 6 MONTHS OLD, otalgia x >48h, ill appearance –> antibiotics

<6 months or > 6 months with severe OM treat with high dose amoxicillin 90mg/kg/day DIV BID or amox/clav 90mg/kg/day if had amoxicillin in last 30 days

<2 yo treat for 10 days
2-5 yo treat for 7 days
>6 yo treat for 5-7d

Question 8

Case scenario
patient OT 1 yo male, reports to hospital with a 3 day history of otorrhea, fever 102, decreased appetite and irritability. Provider suspects AOM and wants an ABX regimen recommendation. Patient has not received ABX recently
NKDA
what if patient had an amoxicillin allergy (rash and hives)?

Answer 8

patient classifies as severe AOM due to otorrhea and symptoms lasting over 48 hours.

recommend amoxicillin 90mg/kg/d DIV BID for 10 days

if amox allergy do 2nd or 3rd gen cephalo

Question 9

first line for pharyngitis
pathogen(s)?
what if mild PCN allergy? severe PCN allergy?

Answer 9

amoxicillin or penicillin
if mild allergy do 2nd or 3rd gen cephalo
if severe allergy do clarithro or azithro or clinda

Question 10

when do we treat acute sinusitis
tx of choice?

Answer 10

sx >10d
T >102 >3d
sx worsen after improvement
amox/clav

Question 11

pertussis
what kind of bacteria is bordatella pertussis
tx?

Answer 11

G- coccobacilli
azithromycin or clarithromycin

Question 12

Patient 61 yo male admitted to ED with suspicion of COPD exacerbation.
What qualifies as COPD exacerbation? How do we treat it?
QTc 510

Answer 12

patient must have inc SOB, inc sputum volume and increased sputum purlence. If purulence is present, only need one other sx.
treat with azithromycin 500mg PO QD x3d or z pak
however, patient’s QTc is prolonged (normal is 350-450 in males) so alternative is doxycycline 100mg po QD-BID x5-7 days

Question 13

other than antibiotics, what else do we use to treat a COPD exacerbation

Answer 13

prednisone 40mg po QD x5 days
MDI
supp oxygen

Question 14

patient is prescribed prednisone 40mg po QD for 5 days for copd exacerbation. hospital pharmacy only has methylprednisolone. What is the equivalent dose

Answer 14

4mg MEPN = 5mg prednisone

4mg MEPN/5mg pred = x mg MEPN/40mg pred

32mg MEPN po once daily or in divided doses

Question 15

what is the goal O2 saturation in a COPD patient

Answer 15

88-92%

Question 16

CAP
common pathogens
treatment for a healthy individual (no comorbidities)

Answer 16

s pneumo, h inf, m pneumo

high dose amoxicillin 1g TID
or
doxycycline
or
macrolide if local PNA resistance <20

Question 17

severe CAP is classified as a patient with ______________________
treatment?

Answer 17

comorbidities (heart, lung, liver, renal disease, DM, AUD, malignancy, asplenia)
treatment is a beta lactam PLUS macrolide
amox/clav or CTX + azithro or clarithro

OR

levofloxacin/ciprofloxacin monotherapy

Question 18

when do we add MRSA or pseud coverage in CAP

Answer 18

hospitalized and received IV ABX in last 90d

Question 19

HAP/VAP
what are MRSA risk factors
how does this change therapy

Answer 19

IV ABX last 90 days
resistance >20%
hx MRSA
+ MRSA swab

need to add MRSA coverage with vanco or linezolid

Question 20

HAP/VAP
what are pseud risk factors
how does this change therapy

Answer 20

IV ABX last 90d
G- resistance >10%
hospitalized >5d prior to HAP/VAP onset (has been in hospital for a while prior to HAP/VAP)

need double pseud coverage

Question 21

Patient Case
Patient admitted 10 days ago for severe COPD exacerbation and has developed a fever, cough and lethargy in the last 48 hours. CXR showed new bilateral infiltrates. What would you recommend for treatment and why
Last hospitalization was 2 months ago for cellulitis (received IV SMX/TMP).
local MRSA resistance 18%
local G- resistance 12%

Answer 21

recommend MSSA, double pseud and vanco coverage since
1. hospitalized in last 90d w IV ABX (MRSA and double pseud cov needed)
2. has been in hospital for >5 days prior to HAP onset (need double pseud)
3. local pseud resistance is >10%

options for pseud include
pip/tazo, cefepime, levoflox, meropenem

options for MRSA coverage include vanco, linezo

examples:
pip/tazo + cefepime + vanco
pip/tazo + cipro + vanco
cefepime + cipro + linezo

Question 22

latent TB treatment options

Answer 22

rifampin 600mg po qd x4 mo
or
isoniazid (INH) 300mg QD x6-9mo
or
rifampin and INH daily x 3mo

Question 23

active TB treatment

Answer 23

RIPE
rifampin 10mg/kg po qd
isoniazid 5mg/kg
pyrazinamide 20-25mg/kg po qd
ethambutol 15-20mg/kg po qd

Question 24

_________ is added in RIPE treatment of active TB to reduce the risk of INH-induced peripheral neuropathy

Answer 24

vitamin B6 (pyridoxime)

Question 25

rifampin is a CYP______ inducer/inhibitor and will inc/dec plasma concentrations of _____________________ _____________________ _____________________ and should not be used with

Answer 25

rifampin is a CYP1A2, 2C8, 2C19, 3A4 inducer and will decrease Cp of protease inhibitors warfarin po contraceptives and should NOT be used with warfarin or dabigatran

Question 26

infective endocarditis treatment if virdans group strep

Answer 26

penicillin or CTX +/- gentamicin

Question 27

infective endocarditis treatment if MSSA

Answer 27

nafcillin or cefazolin + gentamicin + rifampin if prosthetic valve

Question 28

infective endocarditis treatment if MRSA

Answer 28

vanco + gentamicin and rifampin if prosthetic valve

Question 29

infective endocarditis treatment if enterococci? What if its VRE?

Answer 29

ampicillin + gent + high dose CTX if VRE --> dapto or linezolid

Question 30

patient with a prosthetic valve and a history of infective endocarditis from a root canal is getting another root canal (crazy right) next week. What should he take for ppx?

Answer 30

amoxicillin 2g PO 30-60 minutes before the procedure

Question 31

first line for SBP treatment

Answer 31

CTX x5-7d due to concern for strep, proteus, e coli, kleb)

Question 32

systemic s/sx of SSTI

Answer 32

T> 100.4 HR >90 WBC >12,000 or <4,000

Question 33

impetigo appearance treatment

Answer 33

honey-colored crusts, non-purulent local lesions - mupirocin topical many lesions - cephalexin 250-500mg PO QID or dicloxacillin 150-500mg PO QID

Question 34

folliculitis/fuurnicle/carbuncle treatment

Answer 34

#1 = I + D #2 = SMX/TMP DS 1-2t PO BID or doxy 100mg po BID

Question 35

cellulitis pathogens treatment with duration

Answer 35

strep (pyogenes or GAS), staph (MSSA) cephalexin 500mg PO QID x5d dicloxacillin 500mg PO QID x5d beta lac allergy --> clinda

Question 36

purulent abscess likely pathogens treatment

Answer 36

staph (CA MRSA, MSSA) #1 = source control #2 = I + D #3 = SMX/TMP DS PO BID or doxy 100mg PO BID or minocycline or clinda

Question 37

necrotizing fascitis pathogens treatment

Answer 37

s pyogenes, s aureus (MRSA), e coli (G-), anaerobes vanco or linezo + B lac + clinda

Question 38

DFI what do we need to cover treatment options and duration

Answer 38

need to cover G+/- anaerobes, and (possibly) MRSA, pseud, GAS, enterobacter, proteus, klebsiella amp/sul pip/tazo meropenem moxifloxacin CTX, cefotaxime, levoflox, cipro) + metronidazole and can add vanco/dapto/linezo for MRSA if needed x1-2 weeks non-severe x2-4 weeks severe x4-6 weeks if limb-threat or involved bone, joint

Question 39

acute uncompl cystitis treatment options and duration

Answer 39

macrobid (nitrof) 100mg PO BID x5 days SMX/TMP 1 DS tab PO BID x3 days fosfomycin 3g x1 dose

Question 40

acute pyelonephritis treatment options and duration

Answer 40

local FQ resistance-dependent <10%: cipro 500mg PO BID x5-7d levoflox 750mg PO QD x5-7d >10%: CTX 1g IV/IM x1 ertapenem 1g IV/IM x1 AG extended int dosing

Question 41

when do we treat a pregnant patient with a UTI? treatment options?

Answer 41

always! especially if UA shows >10^5 CFU bacteria. amoxicillin cephalexin fosfomycin

Question 42

c diff first episode treatment

Answer 42

vancomycin 125mg PO QID x10d or fidaxo 200mg PO QID x10d or metrondazole 500mg PO TID if above unavail

Question 43

c diff second episode treatment

Answer 43

vancomycin standard + pulse taper or vanco standard if metronidazole used 1st time or fidaxo 200mg PO BID x10d

Question 44

c diff third episode treatment

Answer 44

vanco standard + long pulse taper or vanco standard + rifaximin or fidaxo BID x10d or fecal microbiota transfer

Question 45

what warrants UTI ppx? what do we use?

Answer 45

>/= 3 episodes / year SMX/TMP SS PO QD or nitrofurantoin 50mg PO QD or SMX/TMP 1 tablet after sexual intercourse

Question 46

chlamydia s/sx treatment

Answer 46

genital discharge or asx non preg - doxy100mg PO BID x7d preg - azithro 1g po x1

Question 47

gonorrhea s/sx treatment

Answer 47

genital discharge or asx CTX (includes pregnant pts) <150kg --> 500mg IM x1 >150kg --> 1g IM x1 + doxy if cant rule out chlamydia

Question 48

b vag s/sx treatment

Answer 48

vaginal disch + fishy odor + pH >4.5 + little to no pain metronidazole 500mg po BID x7d or metronidazole 0.75% gel appl QD x5d or clinda 2% crm appl qhs x7d or tinidazole 2g po qd x2d or clinda 300mg po bid x7d or secnidazole 2g po x1

Question 49

trich s/sx treatment

Answer 49

yellow/green frothy discharge + pH >4.5 + pain with intercourse female: metronidazole 500mg PO BID x7d male: 2g PO x1

Question 50

syphillis s/sx treatment

Answer 50

depends on stage of infection primary, secondary or early latent || \/ Pen G 2.4 million units IM x1 latent or tertiary (>1year ago acquired) || \/ Pen G 2.4 million units IM qweek x3 weeks

Question 51

genital warts treatment

Answer 51

imiquimod cream

Question 52

patient presents to primary care office with urinary urgency, increased frequency and burning. female, 68 yo CrCl 48 mL/min treatment options?

Answer 52

macrobid CI 2/2 CrCl <60 SMX/TMP 1 DS tablet PO BID x3 days would need to renally adjust if crcl <30!

Question 53

Patient admitted for uti. 72 yo female PMH insulin-dep DM, epilepsy, schizophrenia, failure to thrive, HTN, HLD, afib. pyelonephritis. treatment options? QTc = 510

Answer 53

concern for psych, tendon rupture, BG changes, seizures, QTc prolongation FQ (levo or cipro) not best option can do SMX/TMP or B lac x7-10 days

Question 54

when is partner treatment warranted

Answer 54

gonorrhea chlamydia syphilis

Question 55

treatment for neurosyphilis

Answer 55

Pen G 3-4 million units IV q4h x10-14d

Question 56

rocky mountain fever treatment

Answer 56

doxy 100mg PO BID x5-7d

Question 57

lyme disease treatment

Answer 57

doxy 100mg po BID x10d

Question 58

Ehrlichosis treatment

Answer 58

tickborne disease doxy 100mg PO BID x7-14 days