Gram Positive only antibiotics

Question 1

What is the MOA of Vancomycin?

Answer 1

inhibits cell wall synthesis
time dependent, bactericidal against Staph and Strep, but is bacteriostatic against enterococci

Question 2

What are the main uses of Vancomycin?

Answer 2

GRAM POSITIVE infections, often used empirically when gram (+) suspected
-streptococcus spp (including strep pneumoniae)
-staphylcoccus spp. (MSSA and MRSA) DRUG OF CHOICE FOR MRSA
-often used empirically against enterococcus infections but Vancomycin Resistant Enterococcus is an issue
-oral vancomycin is ONLY used for C.diff infections

Question 3

When should Vancomycin use be avoided?

Answer 3

-gram negative infections
-gut anaerobes
-atypical organisms

Question 4

How is Vancomycin eliminated?

Answer 4

renally eliminated, dose adjustment needed and good UTI drug

Question 5

What are the adverse drug reactions of Vancomycin?

Answer 5

-infusion reaction aka flushing reaction aka red mans syndrome
-hypersensivity reaction
-fever
-nephrotoxicity
-ototoxicity

Question 6

What is the MOA of linezolid/tedizolid?

Answer 6

inhibits bacterial protein synthesis
weak inhibitor of monoamine oxidase- DRUG INTERACTIONS

Question 7

What is the main uses of linezolid/tedizolid?

Answer 7

-streptococcus spp (including strep pneumoniae)
-staphylococcus (MSSA and MRSA), good penetration into lungs so could be used for pneumonia caused by staph.
-enterococcus (effective against vancomycin resistant enterococcus)

Question 8

When should linezolid/tedizolid use be avoided?

Answer 8

-gram negative infections
-gut anaerobes
-atypical organisms

Question 9

What are the unique pharmacokinetics of linezolid/tedizolid?

Answer 9

-linezolid= only 35% eliminated not an ideal UTI drug and tedizolid is not used as an UTI drug
-large volume of distribution so not ideal for bloodstream infections

Question 10

What are the adverse drug reactions of linezolid/tedizolid?

Answer 10

-GI (nausea, diarrhea)
-headache
-linezolid= thrombocytopenia (see with use > 2 weeks)
-serotonin syndrome (avoid drugs that also increase serotonin)

Question 11

What is the MOA of daptomycin?

Answer 11

binds cell membrane and causes rapid depolarization
bacterialcidal, concentration-dependent

Question 12

What are the main uses of daptomycin?

Answer 12

GRAM POSITVE infections
-streptococcus spp(including strep pneumoniae)
-staphylococcus spp. (MSSA and MRSA)
-enterococcus spp. (effective against vancomycin resistant enterococcus)

Question 13

When should daptomycin use be avoided?

Answer 13

-lung infections (inactivated)
-gram negative infections
-gut anaerobes
-atypical organisms

Question 14

What are the adverse drug reactions of daptomycin?

Answer 14

-GI (nausea, diarrhea)
-headache
-rash
-myopathies with elevations of CPK, may present with myalgias and muscle weakness)

Question 15

When would oral vancomycin be used?

Answer 15

C. diff infections

Question 16

What is the drug of choice for MRSA?

Answer 16

vancomycin

Question 17

What drugs may be used to treat vancomycin resistant enterococcus (VRE)?

Answer 17

-linezolid/tedizolid
-daptomycin

Question 18

What are the main uses of Telavancin, Dalbavancin, Oritavancin?

Answer 18

GRAM POSITIVE infections, all indicated for soft tissue infections
-streptococcus (including strep pneumoniae)
-staphylococcus (MSSA and MRSA)
-vancomycin susceptible enterococcus spp. (NOT a great choice for VRE)

Question 19

What are the half lives of Telavancin, Dalbavancin, and Oritavancin?

Answer 19

dalbavancin and oritavancin is hundreds of hours, whereas telavancin is 7-10 hours

Question 20

What may be a hurdle to the use of Telavancin, Dalbavancin, or Oritavancin?

Answer 20

extremely expensive

Question 21

What is the MOA of Sulfamethoxazole/Trimethoprim?

Answer 21

-gram positive infections= Staphylococcus (MRSA and MSSA), 2nd line for Listeria infections, Nocardia
-gram negative infections= PEK (Proteus, E.coli, Klebsiella (not K. aerogenes), some SPACE (Serratia, Enterobacter (also K. aerogenes), Stenotrophomonas maltophilia
-Pneumocystis jiroveci
-Toxoplasmosis

Question 22

When should Sulfamethoxazole/Trimethoprim be avoided?

Answer 22

-Streptococcus
-Enterococcus
-gut anaerobes
-atypical organisms

Question 23

What are the adverse drug reactions of Sulfamethoxazole/Trimethoprim?

Answer 23

-GI (nausea,vomiting, abdominal pain)
-hypersensitivity reactions
-rash, potential steven johnsons syndrome (SJS)/toxic epidermal necrolysis
-fever
-blood dyscrasias (the “-penias”, decrease in all blood lines)
-photosensitivity
-hyperkalemia

Question 24

What is the drug of choice for PJP pneumonia (Pneumocystis jiroveci)?

Answer 24

Sulfamethoxazole/ Trimethoprim