Antibiotic Indications: Drugs & Bugs

Question 1

Penicillin G & V.

Answer 1

Streptococcal species, resistance in
some species (S. pneumoniae, S.
anginosus group, viridians group);
mouth anaerobes; syphilis; poor Staph

Question 2

oxacillin (IV); nafcillin

IV); dicloxacillin (PO

Answer 2

Methicillin-sensitive S. aureus (MSSA)

Question 3

Ampicillin (IV, PO);

amoxicillin (PO)

Answer 3

Streptococcus (DoC for Enterococcus);

mouth anaerobes; Listeria, E. coli, Proteus

Question 4

Piperacillin (IV);

Ticarcillin

Answer 4

Activity of aminopenicillins; Pseudomonas, Enterobacter, Serratia

Question 5

Zosyn IV (piperacillin +
tazobactam);
Augmentin PO
(amoxicillin +
clavulanate)

Answer 5

Retention of spectrum of parent drug
with increased activity against β-
lactamase producing organisms
(S. aureus, gut anaerobes, all
Haemophilus, E. coli)

Question 6

Cefazolin (IV);

cephalexin (oral

Answer 6

S. aureus; strep (NO Enterococcus); E.
coli, Proteus, Klebsiella; mouth
anaerobes

Question 7

Cefuroxime

Answer 7

Less. S. aureus coverage; 1st
generation plus Haemophilus (including
penicillinase strains); above and below
diaphragm anaerobes

Question 8

Cefoxitin; cefotetan

Answer 8

More active against E. coli & Klebsiella

than 1st generation; B. fragilis

Question 9

Ceftazadime (IV);
cefpodoxime (PO);
ceftriaxone (IV)

Answer 9

Ceftazidime: poor gram-positive activity
Ceftriaxone less active against MSSA
than 1st generation cephs, but active
against Strep;
enhanced activity against gramnegatives
Ceftazdime: Pseudomonas

Question 10

Cefepime (IV)

Answer 10

3rd generation, plus Staphylococcus

coverage

Question 11

Ceftaroline (IV)

Answer 11

Gram positive-MRSA, MSSA,
Streptococci, E. faecalis not faecium
Gram negative activity similar to
ceftriaxone

Question 12

Imipenem - cilastatin;
Meropenem;
Ertapenem; Doripenem
(all IV)

Answer 12

Broad spectrum (excludes MRSA)
Ertapenem: not effective against
Pseudomonas, Acinetobacter
Used for highly-resistant organisms

Question 13

Aztreonam (IV)

Answer 13

Gram- aerobic bacilli including

Pseudomonas, no G+, no anaerobes

Question 14

Vancomycin (IV, PO)

Answer 14

G+s only (MRSA, Enterococcus,
coagulase-negative Staph, Strep)
PO: C. difficile

Question 15

Dalbavancin;

Telavancin; Oritavancin

Answer 15

Similar to vancomycin but active against

VRE & more anaerobe coverage

Question 16

Daptomycin (IV)

Answer 16

G+ cocci only; use for VRE, VRSA

Question 17

Colistin (IV, INH)

Answer 17

G- only; usually reserved for
Pseudomonas species resistant to all
other antibacterials

Question 18

Ciprofloxacin (IV, PO)

Answer 18

Enterobactericeae, Pseudomonas, Atypicals

Question 19

Levofloxacin (IV, PO);

Moxifloxacin (IV, PO

Answer 19

Adds pneumococcus (Strep
pneumoniae) to spectrum of 1st
generation fluoroquinolones.
Levofloxacin: Pseudomonas
Moxifloxacin: No Pseudomonas, but has
anaerobic activity

Question 20

Metronidazole (IV, PO

Answer 20

Anaerobes excluding Actinomyces;
Peptostreptococcus (DoC for C.
difficile); some protozoa (Giardia, Trichomonas, Entamoeba); H. pylori

Question 21

Rifampin (IV, PO)

Answer 21

Mycobacterium tuberculosis; Staph

aureus

Question 22

Gentamicin; tobramycin

Answer 22

Extremely effective against G- rods;
ineffective against anaerobes due to an
oxygen-dependent uptake mechanism,

Question 23

Doxycycline;
Minocycline (both IV,
PO

Answer 23

utility for Gram+ (S. pneumoniae,
MRSA); very effective against
intracellular pathogens (mycoplasma,
chlamydia, legionella, rickettsia)

Question 24

Tigecycline (IV)

Answer 24

Broad spectrum including MRSA, VRE,
Enterobacteriaceae, and anaerobes.
DOES NOT have activity against
Pseudomonas. Often one of few drugs
effective against carbapenem-resistant
Enterobacteriaceae

Question 25

Clindamycin (IV, PO)

Answer 25

ONLY G+ cocci & anaerobes: CA-MRSA/MSSA, Strep, Staph (resistance in Group B strep and S. aureus increasing), Mouth anaerobes

Question 26

Azithromycin (Z-Pak

PO, IV))

Answer 26

Effective for intracellular pathogens
(mycoplasma, chlamydia, legionella). H.
influenzae; ; S. pneumoniae (high level
of resistance)

Question 27

Linezolid & Tedizolid

both IV, PO

Answer 27

Gram+ organisms; MRSA, MSSA,

Enterococcus including VRE

Question 28

Trimethoprim

Answer 28

Uncomplicated UTIs; Pneumocystis
pneumonia & Toxoplasmosis infections
in immunocompromised patients

Question 29

Sulfamethoxazole

Answer 29

Uncomplicated UTIs; Pneumocystis
pneumonia & Toxoplasmosis infections
in immunocompromised patients