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Fosfomycin Dosage

Medically reviewed on July 2, 2018.

Applies to the following strengths: 3 g

Usual Adult Dose for Cystitis

3 g (1 sachet) orally once as a single dose

-This drug should not be used for the treatment of pyelonephritis or perinephric abscess.

Use: For the treatment of uncomplicated urinary tract infections (acute cystitis) in women due to susceptible strains of Escherichia coli and Enterococcus faecalis

Usual Adult Dose for Transurethral Prostatectomy

3 g (1 sachet) orally on the evening before the procedure and then 3 g orally on the evening after the procedure

-Not approved by US FDA.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available


Safety and efficacy have not been established in patients younger than 12 years; only approved for use in women 18 years or older.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice:
-May take with or without food
-Do not take this drug in its dry form; always mix with water prior to ingestion; take immediately after dissolving in water.

Reconstitution/preparation techniques:
-The contents of 1 sachet should be dissolved in 3 to 4 ounces of water (1/2 cup) immediately prior to administration; hot water should not be used.

-Urine specimens for culture and susceptibility testing should be obtained before and after oral therapy.
-If bacteriuria persists or reappears after use of this drug, alternative therapeutic regimens should be selected based on microbiological studies.

Patient advice:
-If symptoms do not improve in 2 to 3 days after taking the single oral dose, contact healthcare provider promptly.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.