Fosfomycin

General

  • Type: Antibiotic
  • Dosage Forms: oral
  • Common Trade Names: Monurol

Adult Dosing

  • Uncomplicated UTI: 3g PO x 1

Pediatric Dosing

  • >12 y/o: 3 g PO x 1

Special Populations

  • Pregnancy Rating: B
  • Lactation Risk: Infant risk cannot be ruled out
  • Renal Dosing: Half life increased in renal impairment, no specific adjustment
  • Hepatic dosing: no adjustment

Contraindications

  • Allergy to class/drug
  • Caution if hepatic impairment
  • Caution if recent antibiotic-associated colitis

Adverse Reactions

Serious

  • Angioedema
  • Aplastic Anemia
  • Asthma Exacerbation
  • Hepatic Necrosis
  • Toxic Megacolon
  • C. difficile diarrhea

Common

  • Diarrhea
  • Vaginitis
  • Rhinitis
  • nausea
  • headache
  • dizziness
  • back pain
  • abdominal pain
  • dysmenorrhea

Pharmacology

  • Half-life: 5.7 hours
  • Metabolism:
  • Excretion: Urine 38%, Feces 18%
  • Mechanism of Action: Bactericidal, inhibits cell wall synthesis

Antibiotic Sensitivities[1]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G X1
Strep. Pneumoniae S
Viridans strep X1
Strep. anginosus gp X1
Enterococcus faecalis S
Enterococcus faecium I
MSSA S
MRSA S
CA-MRSA S
Staph. Epidermidis X1
C. jeikeium X1
L. monocytogenes R
Gram Negatives N. gonorrhoeae X1
N. meningitidis X1
Moraxella catarrhalis X1
H. influenzae X1
E. coli S
Klebsiella sp S
E. coli/Klebsiella ESBL+ S
E coli/Klebsiella KPC+ S
Enterobacter sp, AmpC neg S
Enterobacter sp, AmpC pos S
Serratia sp X1
Serratia marcescens S
Salmonella sp S
Shigella sp X1
Proteus mirabilis X1
Proteus vulgaris S
Providencia sp. X1
Morganella sp. X1
Citrobacter freundii X1
Citrobacter diversus X1
Citrobacter sp. X1
Aeromonas sp X1
Acinetobacter sp. R
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 X1
Mycoplasm pneumoniae X1
Rickettsia sp X1
Mycobacterium avium X1
Anaerobes Actinomyces X1
Bacteroides fragilis X1
Prevotella melaninogenica X1
Clostridium difficile X1
Clostridium (not difficile) X1
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

See Also

References

  1. Sanford Guide to Antimicrobial Therapy 2014