Streptogramins

Question 1

MOA

Answer 1

Inhibit protein synthesis by binding to 50S subunit

Bacteriostatic–> Time-dependent significant PAE

Question 2

MOR

Answer 2

Alteration of ribosomal binding site (erm gene)

Question 3

Spectrum of activity

Answer 3

Gram (+) aerobes:
- PRSP
- Enterococcus faecium ONLY; including VRE
- MSSA
- MRSA

Question 4

Absorption

Answer 4

ONLY PARENTERAL

Question 5

Distribution

Answer 5

Minimal penetration into CSF

Penetrates into extravascular tissue, lung, bile, gallbladder, skin

Question 6

Elimination

Answer 6

BOTH agents are converted to active metabolites by CYP enzymes eliminated by hepatic or biliary elimination

NO DOSE ADJUSTMENTS

Question 7

Clinical uses

Answer 7

Only considered when vancomycin, daptomycin, and linezolid cannot be used

VRE bacteremia

Question 8

Drug interactions

Answer 8

CYP3A4

Lipid-lowering agents-HMG-CoA reductase inhibitors

Immunosuppressive agents: cyclosporine, tacrolimus

Carbamazepine

Question 9

Adverse effects

Answer 9

Venous irritation–>central vein preferred

GI–> N/V/D

Myalgias, arthralgia

Rash