Spectrum of activity

Question 1

Methicillin-Susceptible Staphylococcus aureus (MSSA)

Answer 1

B-lactam drugs:
Nafcillin (IV), Oxacillin, Dicloxacillin (PO)
Unasyn, Zosyn
Cefazolin (IV)*, Cephalexin (PO), Cefuroxime (IV/PO), Ceftriaxone (?), Ceftaroline
Imipenem and Doripenem (rarely used for MSSA)
Macrolides:
Erythromycin, Clarithromycin, and Azithromycin (rarely used for MSSA)
FQ:
Levofloxacin and Moxifloxacin (rarely used for MSSA)
Gram-positive and vanc:
Vancomycin† (only in patients who cannot receive β-lactams)
Quinupristin/Dalfopristin (Synercid©)
Linezolid, Tedizolid
Daptomycin
Telavancin, Dalbavancin, Oritavancin
miscellaneous:
Doxycycline, Minocycline, Tetracycline analogs (rarely used for MSSA)
Trimethoprim-sulfamethoxazole
Clindamycin

Question 2

Methicillin-Resistant Staphylococcus aureus (MRSA)

Answer 2

Vancomycin*
Quinupristin/Dalfopristin (Synercid)
Linezolid† (in patients who cannot tolerate vancomycin), Tedizolid
Daptomycin† (in patients who cannot tolerate vancomycin)
Telavancin, Dalbavancin, Oritavancin
Ceftaroline
Minocycline, Tetracycline analogs (rarely used for MRSA)
CA-MRSA SSTIs: Clindamycin, TMP-SMX, Delafloxacin

Question 3

Enterococcus spp. Susceptible to Ampicillin and Vancomycin

Answer 3

Ampicillin* (IV or PO, depending on infection) and amoxicillin (PO, UTIs only)
Vancomycin† (only in patients who cannot receive ampicillin)
Quinupristin/Dalfopristin (Synercid)
Linezolid, Tedizolid
Daptomycin
Telavancin
Doxycycline and Tetracycline analogs (rarely used for Enterococcus)

Question 4

Vancomycin-Resistant Enterococcus spp. (VRE) Resistant to Ampicillin

Answer 4

If the VRE is S to ampicillin, ampicillin is the drug of choice.
Linezolid* (only if patient not on SSRI and platelet count >50-100), Tedizolid
Daptomycin* (if patient on SSRI)
Quinupristin/Dalfopristin (Synercid©) – 3rd line, only active against VRE faecium
Oritavancin

Question 5

Pseudomonas aeruginosa

Answer 5

Ticarcillin
Piperacillin*
Piperacillin-tazobactam (Zosyn©)
Ceftazidime, Cefepime, Cefiderocol
Meropenem or Doripenem†
Aztreonam
Ciprofloxacin, Levofloxacin, Delafloxacin
Gentamicin, Tobramycin or Amikacin (primarily in combination with β-lactams)
Colistin, Polymyxin b

Question 6

Atypical Bacteria such as Legionella, Mycoplasma, Chlamydia

Answer 6

Erythromycin, Clarithromycin or Azithromycin*
Levofloxacin, Ciprofloxacin, Delafloxacin, Moxifloxacin*
Doxycycline† and Tetracycline analogs

Question 7

Monomicrobial infection due to Bacteroides spp

Answer 7

Metronidazole*
Clindamycin
Unasyn© or Zosyn©†
Imipenem, Meropenem, Doripenem or Ertapenem†

Question 8

Polymicrobial infection with Bacteroides spp. and Gram-negative aerobes

Answer 8

Unasyn© alone (limited gram-negative coverage)
Zosyn© alone*
Imipenem, Meropenem, Doripenem or Ertapenem alone†
Cefoxitin or Cefotetan alone
Ceftriaxone or Cefepime with Metronidazole†
Ciprofloxacin or Levofloxacin with Metronidazole†
Tetracycline analogs

Question 9

Clostridioides difficile colitis

Answer 9

Oral Vancomycin
Metronidazole

Question 10

Drugs contraindicated in pregnancy

Answer 10

Metronitazole - pregnancy B
TMP-SMX - category C
Fluroquinolones
Tetracyclines
Telavancin

Question 11

Drugs that interact with Warfarin

Answer 11

Macrolides- Clarithromycin,Erythromycin
Fluroquinolones
TMP-SMX
Metronidazole

Question 12

Drugs that interact with cations

Answer 12

FQ
Tetracyclines

Question 13

Drugs that cause QTC prolongation

Answer 13

Macrolides- Azithromycin, Erythromycin, Clarithromycin
FQ - Levofloxacin, moxifloxacin, Delafloxacin, Ciprofloxacin
Telavancin

Question 14

Drugs that interact with alcohol and cause disulfiram reaction

Answer 14

Cephalosporins - Cefamandole, Cefotetan, Cefmetazole, Cefoperazone, Moxalactam (all have 5-NMTT side chain that causes thing)
Metronidazole

Question 15

Drugs that cause Nephrotoxicity

Answer 15

Vancomycin
Telavancin, oritavancin, dalbavancin
Aminoglycosides - gentimicin, Tobramycin, Amikacin, Streptomycin, and Plazomicin
TMP/SMX, sulfadiazine, ciprofloxacin, levofloxacin, and moxifloxacin
Nafcillin
Polymyxin B and CMS

Question 16

What drugs must be renally adjusted

Answer 16

Penecillins, Cephalosporins, cabapenems, Monobactams
Macrolide- clarithromycin (CrCl <30)
FQ- Levofloxacin
Vancomycin
Daptomycin
Telavancin, Dalbavancin
Aminoglycosides - Gentamicin, Tobramycin, Amikacin, Streptomycin, and plazomicin
Tetracycline
TMP-SMX (CrCl <30)
CMS

Question 17

What drugs do not need renal adjustment

Answer 17

Penicillinase-Resistant Penicillins - Nafcillin, Oxacillin,
Ureidopenicillin: piperacillin

Cephalosporins - 3rd generation Ceftriaxone, Cefoperazone

Macrolide - Azithromycin and Erythromycin
FQ- Moxifloxacin, Cirpofloxacin
Synercid (must adjust in hepatic insufficiency)
Oxazolidinones - linezolid and tedizolid
Oritavancin
Doxycycline and Minocycline
Clindamycin
Metronidazole (hepatic dose adjustments)

Question 18

drugs with 5-NMTT side chain that leads to Hypoprothrombinemia

Answer 18

Cefamandole, Cefotetan, Cefmetazole, Cefoperazone, Moxalactam

Question 19

CNS penetration

Answer 19

Cephalosporins- Cefuroxime (no longer recommended for tx of meningitis), Ceftriaxone, Ceftazidime, Cefpodoxime, Cefepime
Carbapenems - Meropenem
Monobactam: Aztreonam
Linezolid and tedizolid
Metronidazole
TMP/SMX
Vancomycin
Metronidazole

Question 20

Erythromycin and Clarithromycin drug interactions

Answer 20

Inhibitors of CYP450 and can increase any of the following drugs
Theophylline, Carbamazepine, Valproate, Cyclosporine, Digoxin, Phenytoin, Warfarin

Question 21

Synercid Drug interaction

Answer 21

CYP450 3A4
Lipid lowering agents
Cyclosporin, Tarolimus
Carbamazepine

Question 22

linezolid Drug interaction

Answer 22

Inhibit monoamine oxidase - risk of serotonin syndrome in patients with SSRI