oxazolidinones, daptomycin, lefamulin

Question 1

Select the true statement(s).
A. daptomycin resistance occurs frequently with streptococci pathogens
B. tedizolid MOA involves irreversibly binding to pathogen cell membrane
C. daptomycin has a lipophilic decanoyl side chain
D. A and B
E. A and C

Answer 1

correct: C

A. FALSE: enterococci
B. FALSE: daptomycin MOA
C. TRUE
D. nope
E. nope

Question 2

Which of the following is false about daptomycin?
A. daptomycin is only available as an IV formulation
B. its lipophilic decanoyl side chain enables daptomycin to cross the pathogen’s cell membrane
C. daptomycin is excreted unchanged in urine
D. A and B
E. B and C
F. all are false
G. none of the above

Answer 2

correct:

A. TRUE
B. FALSE: despite lipophilic decanoyl side chain, daptomycin is also highly protein bound so poorly crosses cell membrane
C. TRUE
D. nope
E. nope
F. nope
G. nope

Question 3

Which of the following is/are false?
A. clindamycin and chlorphenamine competitively inhibit linezolid
B. daptomycin has high PO absorption
C. daptomycin is primarily eliminated non-renally, thus renal dosage adjustment is not required
D. a resistance mechanism to linezolid includes methylation
E. pulmonary surfactants inactivate daptomycin
F. A and C
G. A, B, C
H. D and E

Answer 3

correct: G

A. FALSE - clindamycin and chloraphenicol
B. FALSE - poor PO absorption, hence only avail as IV
C. FALSE - if CrCl < 30, dose Q48H
D. TRUE
E. TRUE

Question 4

Increased serum creatinine phosphokinase is an AE of...
A. oxazolidinones
B. linezolid only
C. daptomycin
D. lefamulin
E. none of the above
F. all of the above

Answer 4

C - daptomycin

Question 5

Which of the following are available as IV and PO formulations?
A. linezolid
B. tidezolid
C. daptomcyin
D. lefamulin
E. A and C
F. A and B
G. A, B, C
H. A, B, C, D

Answer 5

everyone except daptomycin (only IV b/c not absorbed orally)

Question 6

Which of the following statements is true?
A. taking lefamulin with food increases its bioavailability
B. daptomycin works by interacting with the rRNA of the 50S ribosomal subunit
C. to switch lefamulin tx from IV to PO, divide the IV dose by 4
D. linezolid is metabolized by CYP3A4
E. B and D
F. none of the above

Answer 6

correct: F - none of the above

A. FALSE - taking w/ food further decreases lefamulin bioavailability
B. FALSE - lefamulin
C. FALSE - multiply
D. FALSE - lefamulin

Question 7

Which drug is associated with each of the following AE?

1. red cell plasia
2. rhabdomyolosis
3. thrombocytopenia
4. hypokalemia
5. acute eosinophilic pneumonia
6. increased liver enzymes
7. discoloured tongue and teeth
8. leukopenia
9. optic neuropathy
10. lactic acidosis
11. increased serum creatinine phosphokinase

Answer 7

1. red cell plasia - linezolid
2. rhabdomyolosis - daptomycin
3. thrombocytopenia - linezolid
4. hypokalemia - lefamulin
5. acute eosinophilic pneumonia - daptomycin
6. increased liver enzymes - lefamulin
7. discoloured tongue and teeth - linezolid
8. leukopenia - linezolid
9. optic neuropathy - linezolid
10. lactic acidosis - linezolid
11. increased serum creatinine phosphokinase - daptomycin

Question 8

name a pleuromutilin antibacterial

Answer 8

lefamulin

Question 9

How is each drug primarily excreted?

1. linezolid
2. tidezolid
3. daptomycin
4. lefamulin

Answer 9

linezolid - non-renally
tidezolid - non-renally
daptomycin - excreted unchanged in urine (renally)
lefamulin - excreted mostly in feces, some in urine