Drug/Bug Combos - Cases, PBL, + need to knows

Question 1

Staphylococcus aureus

Answer 1

cloxacillin

Question 2

MRSA

Answer 2

vancomycin

Question 3

Strep pyogenes

Answer 3

penicillin

Question 4

Enteroccus faecalis

Answer 4

ampicillin +gentamicin (synergy)

Question 5

Viridans group streptococci

Answer 5

penicillin or ceftriaxone

e.g. S. mitis

Question 6

Haemophilus influenzae

Answer 6

cefuroxime or amoxicillin/clavulanate

Question 7

Strep pneumoniae

Answer 7

amoxicillin (PO), penicillin or ceftriaxone (IV)

Question 8

Enterobacteriaceae

Answer 8

gentamicin, ciprofloxacin, ceftriaxone

e.g. E. coli, Enterobacter spp. Salmonella spp. Proteus spp.

Question 9

Anaerobes

Answer 9

metrinidazole

e.g. G+ : peptostreptococcus spp. clostridium spp. acintomyces spp. G- : bacteroides

Question 10

Syphilis

Answer 10

organism: Treponema pallidum
Tx: IM benzathine penicillin

Question 11

Giardia

Answer 11

metronidazole

Question 12

4 TB medications

Answer 12

rifampin
isoniazid
pyrazinamide
ethambutol

Question 13

Chlamydia tx

Answer 13

Doxycycline

Question 14

MAC prophylaxis

Answer 14

Azithromycin

Question 15

Toxoplasmosis prophylaxis

Answer 15

TMP/SMX

Question 16

PJP tx

Answer 16

prophylaxis: TMP/SMX
treatment: TMP/SMX with prednisone

Question 17

UTI tx

Answer 17

organism 90% of time E. coli

1st line: Nitrofurantoin
Other empiric options: fosfomycin or amoxicillin/clavulanate
High resistance levels: TMP/SMX, Cipro
If pregnant: Amoxicillin

Question 18

Acute Bronchitis - cause and tx

Answer 18

most common cause: common cold viruses (e.g. rhinovirus)
invasive respiratory viruses cause more sever symptoms (e.g. influenza, adenovirus, parainfluenxa, RSV)

Tx: NO antibiotics. wash hands, stop smoking, fluids, cough suppressants, bronchodilator if coughing for significant amount of time

Question 19

Is ear pain common with colds without it being AOM?

Answer 19

Yes! due to fluid building up in Eustachian tube. If normal movement of tympanic membrane, not AOM

Tx with analgesic

Question 20

Tx of AOM

Answer 20

Children >2 yrs with unilateral AOM: acetaminophen and watchful waiting for 48 hrs

Antibiotics if: not better in 48 hr, eardrum perforated, unresponsive to analgesic, recurrent, < 6 mo old, bilateral, unlikely to return for follow up

Tx: amoxicillin to cover for S. pneumo

Question 21

Otitis Media With Effusion - cause and when do you start to treat

Answer 21

fluid remaining post infection.
not an issue unless prolonged for >3-6 months
50% of children will have fluid in their ears for 1 month post AOM

Question 22

Tx of severe cellulitis in diabetic pt

Answer 22

begin broad and narrow with improvement and C/S results

Piperacillin-Taxobactam, 4th gen cephalosporin (cefepime) or carbapenem

If at risk for MRSA (known colonization, Hx, pop prevalence 30-50%): IV vancomycin

Question 23

Pseudomonas

Answer 23

Ciprofloxacin or Pipercillin-tazobactam

Question 24

Asymptomatic bacteruria tx

Answer 24

No symptoms = no UTI = no antibiotics
very common in elderly pts (50% of nursing home pt)

2 situations to treat: pregnant, urologic procedure

Question 25

VZV tx

Answer 25

acyclovir, famciclovir, and valacyclovir are effective at reducing severity and duration of symptoms and shedding if started withint 72 hours of rash onset

reduce risk of exposing susceptible individuals: neonates, pregnant women, immmunocompromised

Question 26

What skin infection commonly complicates zoster? Organisms, tx

Answer 26

cellulitis 
common organisms: beta-hemolytic strep and staph aureus 
Tx: cephalexin or cloxacillin 
MRSA - vancomycin 
B-lactam allergy - clindamycin

Question 27

What is the complication of zoster leading to long-term pain and paresthesias? Tx

Answer 27

Post-herpetic neuralgia

1st line: Amitriptyline (Tricyclic antidepressant; low dose for pain control) Gabapentin (anticonvulsant; useful for nerve pain)

2nd line: opiods b/c of abuse and addition potential

Question 28

Treatment of mild and severe traveller’s diarrhea

Answer 28

often self-limited (~3 days) so no need for antibiotics
give support therapy (fluids, etc)

if prolonged, severe, or b/c of shigellosis, typhoid fever or cholera treat with abx

Question 29

When are antibiotics contraindicated for diarrhea?

Answer 29

if its caused by enterohemorrhagic E. coli

Question 30

TB treatment

Answer 30

Drug sensitive disease: 2 months of rifampin. pyrazinamide and isoniazid (INH) followed by 4 months of INH and rifampin

If not sensitive to all first line drugs, add ethambutol

Question 31

HSV tx in children

Answer 31

acylovir

note: valacylovir not approved for children

Question 32

Treatment of P. vivax (from PBL case)

Answer 32

Chloroquine followed by primaquine

choloroquine works on erythrocyte stage and primaquine eliminates liver forms