Quinupristin/dalfopristin

Uses

  • Antibiotic: treatment of vancomycin-resistant Enterococcus faecium, as well as nosocomial pneumonias and infections secondary to IV catheters (1)

Administration

  • Dosage Forms: 500mg vials, diluted into 250 mL and given over 60 mins
  • Routes of Administration: IV
  • Common Trade Names: Synercid

Adult Dosing

  • VRE: 7.5mg/kg IV q8 hrs for minimum 7 days
  • skin infections: 7.5mg/kg IV q12 hrs for minimum 7 days

Pediatric Dosing

  • safety and efficacy has not been studied in children

Special Populations

  • Pregnancy Rating: B
  • Lactation risk: unknown whether secreted in human breast milk. Caution should be exercised when administering to nursing mothers. (2)

Renal Dosing

  • no adjustments for renal impairment

Hepatic Dosing

  • dosage may need to be adjusted in patients with cirrhosis, however specific dose modification is not known at this time (2)


Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

Common

  • pain and inflammation at infusion site
  • arthralgias
  • nausea/vomiting/diarrhea
  • rash
  • headache
  • pruritus

Pharmacology

  • Half-life: Quinupristin: 3 hrs; Dalfopristin: 1 hr
  • Metabolism: significantly interacts with the CYP 3A4 system.
  • Excretion:

Antibiotic Sensitivities[1]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G S
Strep. Pneumoniae S
Viridans strep X1
Strep. anginosus gp X1
Enterococcus faecalis R
Enterococcus faecium S
MSSA S
MRSA S
CA-MRSA S
Staph. Epidermidis S
C. jeikeium S
L. monocytogenes S
Gram Negatives N. gonorrhoeae X2
N. meningitidis R
Moraxella catarrhalis S
H. influenzae I
E. coli R
Klebsiella sp R
E. coli/Klebsiella ESBL+ R
E coli/Klebsiella KPC+ R
Enterobacter sp, AmpC neg R
Enterobacter sp, AmpC pos R
Serratia sp X1
Serratia marcescens X1
Salmonella sp R
Shigella sp R
Proteus mirabilis X1
Proteus vulgaris X1
Providencia sp. X1
Morganella sp. X1
Citrobacter freundii X1
Citrobacter diversus X1
Citrobacter sp. X1
Aeromonas sp X1
Acinetobacter sp. X1
Pseudomonas aeruginosa R
Burkholderia cepacia X1
Stenotrophomonas maltophilia X1
Yersinia enterocolitica X1
Francisella tularensis X1
Brucella sp. X1
Legionella sp. X1
Pasteurella multocida X1
Haemophilus ducreyi X1
Vibrio vulnificus X1
Misc Chlamydophila sp X2
Mycoplasm pneumoniae S
Rickettsia sp X1
Mycobacterium avium R
Anaerobes Actinomyces X1
Bacteroides fragilis X1
Prevotella melaninogenica S
Clostridium difficile I
Clostridium (not difficile) X2
Fusobacterium necrophorum X1
Peptostreptococcus sp. X1

Key

  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

References

  • Sanford Guide to Antimicrobial Therapy 2014