infection and treatment

Question 1

mild cellulitis common bugs

Answer 1

streptococci A

Question 2

mod-sev cellulitis common bug

Answer 2

grp A streptococci + MSSA

Question 3

mild cellulitis choice of therapy

Answer 3

penicillin, amoxicillin, cloxacillin, cephalexin, augmentin, clindamycin

Question 4

mod-sev cellulitis treatment

Answer 4

IV route cefazolin, cloxacillin, augmentin, clindamycin

Question 5

empiric mrsa

Answer 5

recent hospitalisation
mrsa colonisation
long term care facility
HD
immunocompromised

Question 6

duration of therapy for mild skin infection

Answer 6

5d , if severe 14d

Question 6

carbuncles bug

Answer 6

staph aureus, beta hemolytic streptococci

Question 7

DFI bugs

Answer 7

mild <2cm: strep + s aureus
mod >2cm but no systemic infection: streptococci + staph aureus + gram -ve + anaerobes
sev: strep + staph + gram-ve + pseudomonas + anaerobes

Question 8

TB 4 months treatment

Answer 8

isoniazide
pyrazinamide
rifapentine
moxifloxacin

Question 9

6months treatment

Answer 9

rifampicin 10mg/kg OD max 600mg OD
isoniazid 5mg/kg max 300mg OD
pyrazinamide 25-35mg/kg OD
ethambutol 20-25mg/kg OD

Question 10

meningitis lumbar puncture indicated for

Answer 10

immunocompromised
hx of cns disease
new onset seizure
papilledema
altered consciousness

Question 11

common bugs of meningitis

Answer 11

<1m: strep agalactiae, ecoli, listeria, klebsiella (SA, ELK) -> ampicillin + ceftoxamine

1-23m: strep pneumonia, neisseria, s.agalactiea, hemophiliz, ecoli (SS, ENH) -> vanco + 3rd gen cephalosporin

2-50yo: (NS) -> vanco + 3rd gen cephalosporin

> 50yo: SNL -> vanco + cephalosporin + ampicillin

Question 12

duration of treatment

Answer 12

neisseria: 7d
hemophilus: 7d
strep pnuemonia: 10-14d
SA: 14-21d
listeria: 21d

Question 13

viral encephalitis treatment

Answer 13

IV acyclovir

crcl>50: 10mg/kg q8h
crcl 25-50: 10mg/kg q12h
crcl: 10-25: 10mg/kg q24h
crcl <10: 5mg/kg q24h

duration: 14-21d

Question 14

invasive candidiasis bugs

Answer 14

candida albican*

C.glabrata, C.parapsilosis, C.tropicalis, C.krusei, Cauris

Question 15

moa of polyenes (amphotericin, liposomal, nystatin), azoles, allylamines(terbinafine)

Answer 15

loss of cell membrane integrity

Question 16

echinocandins moa

Answer 16

loss of cell wall integrity -> inhbiit 1,3,beta glucan synthesis

Question 17

invasive candidiasis treatment

Answer 17

echinocandin 1st line then amphotericin then fluconazole

azoles are resistant to c glabrata

-> continue for 14d after 1st -ve blood culture

Question 18

flucytosine

Answer 18

broad antifungal activity against candida except C krusei

• penetrates fungal cells and converted to fluorouracil which competes with uracil interfering with fungal RNA and protein synthesis
• usually given in combi w another antifungal due to resistance