Infectious Diseases I: Misc. Antibiotics

Question 1

Polymixin class consist of what 2 drugs?

Answer 1

Colistimethate (Colistin)

Polymyxin B

Question 2

Polymyxins coverage

Answer 2

Mostly Gram - bacteria
Enterobacter
E. Coli
Klebsiella pneumoniae
Pseudomonas

Primarily used for MDR Gram - pathogens

Question 3

Why should polymyxins be used in combination with other antibiotics?

Answer 3

High rates of resistance

Question 4

Polymyxins MOA

Answer 4

Colistimethate is prodrug that is turned into colistin

acts as cationic detergent and damages cytoplasmic membrane

Question 5

Colistimethate brand and side effects

Answer 5

Coly-Mycin M

Nephrotoxicity (dose related)
Neurologic disturbances (HA, vertigo, tingling)
rash
neurotoxicity (can leas to resp paralysis)

Question 6

Polymyxin B side effects

Answer 6

same as colistin

Nephrotoxicity (dose related)
Neurologic disturbances (HA, vertigo, tingling)
rash
neurotoxicity (can leas to resp paralysis)

Question 7

CrCL cut-off for polymyxins:

Answer 7

CrCl < 80

adjustment required

Question 8

Chloramphenicol MOA

Answer 8

binds to 50S subunit and inhibits protein synthesis

Question 9

Chloramphenicol coverage

Answer 9

broad coverage
Gram +/-
anaerobes
atypicals

Question 10

Chloramphenicol warnings

Answer 10

aplastic anemia
throbocytopenia
Gray syndrome: circulatroy collapse, cyanosis, coma and death

Question 11

Chloramphenicol dose

Answer 11

50-100 mg/kg/day in 4 doses

rarely used due to serious side effects

Question 12

Clindamycin MOA

Answer 12

Lincosamide class

binds to 50S subunit and inhibits protein synthesis

Question 13

Clindamycin coverage

Answer 13

Most aerobic and anaerobic Gram + bacteria

including CA-MRSA

Question 14

Clindamycin common uses

Answer 14

Purulent and non-purulent skin infections
dental abscesses (alt to beta-lactam)

Question 15

Clindamycin side effects

Answer 15

C. diff colitis (boxed warning)
Severe skin reactions (SJS/TEN/DRESS)
n/v/d
rash, itiching

Question 16

Clindamycin doseing

Answer 16

150-450 mg PO q6h

600-900 mg IV q8h

Question 17

metronidazole/tinidazole MOA

Answer 17

causes loss of structure to bacterial DNA, which inhibits protein synthesis

Question 18

Metronidazole coverage

Answer 18

anaerobes

protozoal infections

Question 19

metronidazole common uses

Answer 19

bacterial vaginosis
trichomoniasis
C. diff
combo therapy for intra-abdominal infections

Question 20

Tinidazole common uses

Answer 20

trichomoniasis
bacyerial vaginosis
protozoa infections

Question 21

metronidazole/tinidazole side effects

Answer 21

Do not use with alcohol (and 3 days after d/c)
CNS effects- seizures, encephalopathy
HA
nausea (take w/ food)
metallic taste
rask, severe skin reactions (SJS/TEN)

Question 22

Tinidazole brand

Answer 22

Tindamax

2 grams PO daily

Question 23

Fidaxomicin brand and use

Answer 23

Dificid

Recurrent C. diff infections

Question 24

Fidaxomicin dose and side effects

Answer 24

200 mg PO BID x10 days

n/v, abdominal pain, GI bleeding

Question 25

Rifaximin brand and coverage

Answer 25

Xifaxan

E. Coli

Question 26

Rifaximin uses

Answer 26

Traveler’s diarrhea: 200 mg TID x 3 days
Reduction of hepatic encephalopathy: 550 mg BID
IBS-D: 550 mg TID x 14 days

Question 27

Rifaximin side effects

Answer 27

Peripheral edema
dizziness
HA
nausea, abd pain
rash

Question 28

Fosfomycin MOA and use

Answer 28

inhibits bacterial cell wall synthesis

used for uncomplicated UTI (cysitis only)

Question 29

Fosfomycin coverage

Answer 29

E. Coli (includ ESBL)

E. faecalis (including VRE)

Question 30

Fosfomycin dose and side effects

Answer 30

3 grams (1 packet) PO x1, mixed with 3-4 oz of cold water

HA
diarrhea
nausea

Question 31

Nitrofurantoin MOA and use

Answer 31

cell wall inhibitor

used for uncomplicated cystitis

Question 32

Nitrofurantoin coverage

Answer 32

E. coli
klebsiella
enterobacter
s. aureus
enterococcus (VRE)

Question 33

Nitrofurantoin renal cut-off

Answer 33

Crcl < 60 per package insert

Crcl < 30 per 2015 update of BEERS list

Question 34

Nitrofurantoin side effects

Answer 34

GI upset (take with food)
HA
Rash
brown urine

Question 35

Nitrofurantoin dosing

Answer 35

Macrobid: given BID (macrocrystal formulation)

Macrodantin: given QID, 50-100 mg QHS For prophylaxis

Question 36

Drug and dose used to eliminate MRSA colonization of the nares

Answer 36

Mupirocin nasal oint

1/2 tube in each nostril BID x 5 days