Drug reference directory
Drug reference

Fosfomycin

Antibacterial

Antibacterial
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
—
none in our sources
PREGNANCY
Manufacturer advises use only if potential benefit outweighs risk.
FDA category + note

Mechanism

Fosfomycin inhibits a very early stage of bacterial cell wall synthesis by acting as a phosphoenolpyruvate analog. It irreversibly inactivates the cytoplasmic enzyme enolpyruvate transferase through covalent binding to its active site. This action blocks the crucial step of adding phosphoenolpyruvate to UDP-N-acetylglucosamine, thereby preventing peptidoglycan precursor formation and exerting its bactericidal effect.

Indications

Acute uncomplicated lower urinary-tract infectionsProphylaxis of urinary-tract infections in transurethral surgical proceduresOsteomyelitis when first-line treatments are inappropriate or ineffectiveHospital-acquired lower respiratory-tract infections when first-line treatments are inappropriate or ineffectiveBacterial meningitis when first-line treatment ineffective or inappropriateAcute uncomplicated cystitisProstatitis (for pathogens resistant to other oral agents)

Dosing

Adult
Oral: For acute uncomplicated lower urinary-tract infections, 3 g as a single dose. For prophylaxis of urinary-tract infections in transurethral surgical procedures, 3 g given 3 hours before surgery, may be repeated once 24 hours after surgery.…
Renal adjustment
Oral: Avoid if eGFR less than 10 mL/minute/1.73 m2. Intravenous: Use with caution if eGFR 40–80 mL/minute/1.73 m2; consult product literature for dose if eGFR less than 40 mL/minute/1.73 m2.
Max dose
24 g daily (with a maximum of 8 g per dose for intravenous administration)

Side effects

Common
Abdominal painDiarrhoeaHeadacheNauseaVomitingDizziness (oral use)Vulvovaginal infection (oral use)Diarrhea
Serious
  • Antibiotic associated colitis
  • Bone marrow disorders (parenteral)
  • Eosinophilia (parenteral)
  • Hepatic disorders (parenteral)
  • Visual impairment (parenteral)
  • Agranulocytosis (parenteral)
  • Asthmatic attack (parenteral)
  • Confusion (parenteral)
  • Leucopenia (parenteral)
  • Neutropenia (parenteral)
  • Tachycardia (parenteral)
  • Thrombocytopenia (parenteral)

Pregnancy & lactation

Pregnancy

Manufacturer advises use only if potential benefit outweighs risk.

Lactation

Manufacturer advises use only if potential benefit outweighs risk, as it is present in milk.

Drug interactions

5 additional unreviewed or low-confidence interactions hidden because their provenance or source detail is insufficient.

Related guidelines

Other Antibacterial drugs

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Textbook-sourced·Sources: Goodman & Gilman 14e, Harrison 22e, Katzung·Updated: 2026-05-13