(foss-foe-mye-sin) ,


(trade name)


Therapeutic: anti infectives
Pregnancy Category: B


Uncomplicated urinary tract infections in women (acute cystitis).


Inactivates an enzyme crucial for bacterial cell wall synthesis.
Decreases adherence of bacteria to uroepithelial cells.

Therapeutic effects

Bactericidal action against susceptible bacteria.
Active against: Enterococcus faecalis and Escherichia coli.


Absorption: Rapidly absorbed and converted to fosfomycin, its active component, resulting in 37% bioavailability.
Distribution: Distributes to kidneys and bladder wall; crosses the placenta.
Metabolism and Excretion: Excreted unchanged in urine (38%) and feces (18%).
Half-life: 5.7 hr.

Time/action profile (bactericidal urine levels†)

POrapid2–4 hrunknown
†Symptoms may take 24–48 hr to subside


Contraindicated in: Hypersensitivity; Pyelonephritis; Lactation: Lactation.
Use Cautiously in: Obstetric / Pediatric: Pregnancy or children <12 yr (safety not established).

Adverse Reactions/Side Effects

Central nervous system

  • dizziness
  • headache
  • weakness


  • pseudomembranous colitis (life-threatening)
  • diarrhea
  • dyspepsia
  • nausea


  • vaginitis


Drug-Drug interaction

Urinary excretion and blood levels are decreased by metoclopramide.


Oral (Adults and Children ≥18 yr) 3 g single dose.


Sachet: 3 g

Nursing implications

Nursing assessment

  • Assess patient for signs and symptoms of cystitis (frequency, urgency, painful urination).
  • Obtain urine specimen for culture and sensitivity before administration.
  • Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of pseudomembranous colitis. May begin up to several weeks following cessation of therapy.

Potential Nursing Diagnoses

Risk for infection (Indications)
Acute pain (Indications)
Deficient knowledge, related to medication regimen (Patient/Family Teaching)


  • Oral: Do not take medication in dry form. Pour entire contents of single sachet into 3–4 oz (½ cup) water and stir to dissolve. Do not use hot water. Drink immediately after mixing. May be administered with or without food.

Patient/Family Teaching

  • Instruct patient on correct preparation of sachet.
  • Instruct patient to notify health care professional immediately if diarrhea, abdominal cramping, fever, or bloody stools occur and not to treat with antidiarrheals without consulting health care professionals.
  • Advise patient to notify health care professional if symptoms have not improved or persist more than 2–3 days after treatment.

Evaluation/Desired Outcomes

  • Improvement in symptoms of acute cystitis within 2–3 days.
Drug Guide, © 2015 Farlex and Partners


® Fosfomycin tromethamine Infectious disease A single dose antibiotic for treating uncomplicated UTIs. See Urinary tract infection.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
During the symposium, a breakthrough prescription drug called Monurol (generic name is Fosfomycin trometamol) was introduced.
By comparison, a single dose of fosfomycin (Monurol) is expensive and generally placed on tier 3 by insurance companies, or not included at all.
These include the penicillins [all B], cephalosporins [all B], aminoglycosides [C or D], sulfonamides [C], and fosfomycin (Monurol) [B].
Its important products are Celexa (depression), Aerobid (asthma), Lorcet (pain), Tiazac (hypertension), Monurol (urinary tract infection) and generic drugs using controlled-release technology.
Fosfomycin (Monurol) is an effective single-dose drug for acute cystitis due to E.
market is fosfomycin (Monurol), which was approved for treating urinary tract infections caused by E.
In the prescription arena Monurol from Forest Laboratories has been cleared by the Food and Drug Administration as what a spokeswoman calls the first onetime, one-dose antibiotic for uncomplicated UTI.
"As a drug that is taken one time and one time only, Monurol is the most convenient antibiotic for uncomplicated urinary tract infection and should have an extremely high rate of compliance among its users," notes Forest Laboratories medical director Harvey Schneier.
A single oral dose of Monurol provides a urinary concentration of the active ingredient that remains effective for more than three and a half days, well over the minimum necessary to destroy the most common urinary tract disease-causing bacteria, escherichia coli, the spokeswoman says.
An orange-flavor, water-soluble powder, Monurol starts destroying the harmful bacteria in the bladder in two to four hours, she notes.