Please note: This is for information only.
Refer to local guidelines for treatment recommendations

Guidance on the use of oral fosfomycin 3g sachets for the treatment of multi-resistant urinary tract infections (UTIs).

Download Patient Information Leaflet click here  



Resistant organisms

In recent years there has been a marked increase, both locally and nationally, in the prevalence of UTIs caused by coliforms that are resistant to both penicillins and cephalosporins (i.e. extended spectrum betalactamase [ESBL] producing organism). Such bacteria tend also to be resistant to other oral antibiotics leaving few therapeutic options. Multi-resistant coliforms tend to occur in the elderly and in many cases bacteriuria is asymptomatic and does not require antibiotic therapy. However in patients with clinically significant infection treatment is indicated.


Fosfomycin 3g sachets
Fosfomycin is an orally active, bactericidal, broad spectrum antibiotic that inhibits bacterial cell wall production. It is currently available in most of Europe, Japan and the USA. It was licensed for UTI treatment in the UK some years ago but was not a commercial success and therefore the UK licence lapsed. Fosfomycin is well absorbed and excreted unchanged in the urine. After a single 3g dose very high urine levels are achieved (concentration in urine remains above MIC of sensitive organisms for up to 48 hours).

Prescribing fosfomycin:

Inclusion Criteria
Patients are eligible for treatment with fosfomycin if the following criteria are fulfilled:

  • They must be suffering from a symptomatic uncomplicated lower UTI
  • A urine specimen must have been examined by the laboratory
  • There must be a significant growth of a fosfomycin-sensitive organism in the urine sample
  • There must be no other suitable oral treatment alternative


Standard Dose: 1 x 3g sachet PO as a single dose on an empty stomach. On occasion a second dose may be prescribed after 3 days.


  • Known hypersensitivity to fosfomycin (or its excipients)
  • Severe renal insufficiency (CrCl <10ml/min)


Pregnancy and breastfeeding

Adverse effects:

  • G.I. disturbance e.g. nausea, diarrhoea, skin rashes (self limiting)

Drug interactions:

Metoclopramide slows absorption of fosfomycin