Urinary antibiotics (grouped by use)
Fosfomycin
Urine infection (cystitis) in womenOccasionally other urine infections when common antibiotics are unsuitable
Start a diary for this antibiotic
Usually prescribed for:Urine infection (cystitis)
Information follows NICE antimicrobial prescribing guidance and the BNF.
Common side effects
- Feeling sick (nausea)
- Loose stools or diarrhoea
- Upset or indigestion-like stomach
- Headache or feeling dizzy
- Thrush (vaginal)
How often each one happens varies by medicine and product, so check your leaflet. Many are mild, but ask your pharmacist or doctor if they are troublesome or do not settle.
Less common side effects
- Being sick (vomiting)
- Wind or bloating
- Itchy skin or mild rash
- Feeling tired
Get medical help straight away if you notice
- Severe allergic reaction: swelling of the face, lips or throat, wheezing or trouble breathing — call 999
- Severe, watery or bloody diarrhoea that will not stop
- Blistering or peeling rash, or mouth or eye sores: stop the medicine and call 999 or go to A&E
Taking it safely
- Usually a single dose for a simple urine infection, so there is no course to finish.
- Dissolve the granules in a glass of water and drink it straight away, on an empty stomach — often at bedtime, after emptying your bladder.
- A single dose does not treat a kidney infection. If you have fever, back or side pain, or feel generally unwell, you need to be assessed again.
- Tell your prescriber if you have ever reacted to an antibiotic, or if you are pregnant or breastfeeding.
Report a side effect
You can report any suspected side effect to the UK Yellow Card scheme at yellowcard.mhra.gov.uk.