Fosfinex 3g

Fosfinex 3g

Fosfinex 3g

Fosfomycin trometamol



Pharmaceutical Group: Antibiotic
Therapeutic indications:
Treatment and prophylaxis (after surgery or trans-urethral diagnostic maneuvers) of acute uncomplicated lower urinary tract infections caused by Fosfomycin-susceptible microorganisms.

Dosage Form(s): Granule for oral solution, packed in sachet
Pregnancy Category: B





Fosfinex 3g is an effective one dose treatment for acute Uncomplicated UTIs. It is a phosphonic acid derivative. The addition of the trometamol(salt) has the effect of making the antibiotic highly soluble and more suitable for oral administration. Fosfomysin trometamol is an effective and tolerable as both trimethoprim and Nitrofurantoin.


Indications and posology and administration
Adults :In the treatment of acute infections of the lower urinary tract caused by germs susceptible to Fosfomycin, the dosage is 1 sachet of Fosfinex in a single dose.

-In the prevention of urinary infections after surgery and trans-urethral diagnosis (trans-urethral diagnostic maneuvers), the normal dose is 1 sachet of Fosfinex three hours before, and another sachet 24 hours after surgery.

-Elderly patients and other clinical situations
In elderly patients, or in other cases (for instance, bed-ridden patients), 2 sachets of Fosfinex can be necessary, administered at a 24-h interval.

-Patients with renal insufficiency
For patients with mild to moderate renal insufficiency, dose adjustments are not needed.


  • The content of the sachet should be dissolved in a half glass of water and drink it preferably before the night resting, after voiding the bladder.



1 sachet



  • If you are allergic (hypersensitive) to Fosfomycin trometamol, or any of the other ingredients of this medicine.
  • Fosfomycin should not be used in patient with impaired renal function(creatinineclearance <80 ml/min) considered in all patients who present with diarrhea following antibiotic use. 
  •  If you are undergoing hemodialysis. 
  •  Children younger 12 years.


Possible side effects

Common side effects (may affect up to 1 in 10 people)
- Digestive problems such as, vomiting, diarrhea, dyspepsia (sensation of fullness with gastric acidity) and nausea.
Rare side effects (may affect up to 1 in 1.000 people):
- Skin reactions such as exanthema (cutaneous rash), urticaria (reddish blisters with itching), angioedema (swelling of the skin) and anaphylaxis (severe allergic or hypersensitivity reactions). In this case, ask your doctor or pharmacist, since you can take a medicine that may make disappear this side effect and should not have to discontinue Fosfomycin treatment.
- Slight increase in the count of eosinophilic leukocytes and platelets (blood cells), as well as some mild petechial reaction (small red points in the skin) and aplastic anemia (reduction of red blood cells).
Other effects that have been reported, and which frequency cannot be estimated from the available data, include:
- Visual impairments, in appetence, phlebitis (formation of thrombi in veins), dyspnea (problems while breathing), bronchospasm (severe difficulty to breath) and cephalea (headache).
- Hepatic changes due to a transient increase in the hepatic enzymes of the liver (transaminases), - Superinfections from resistant bacteria.


Interaction with other medicinal products and other forms of interaction
Simultaneous co-administration with metoclopramide (medicine used to treat nausea and vomiting) may reduce the antibiotic effect of Fosfomycin.
Although no more cases of interaction have been reported, medicines that increase the movement of the stomach or intestines (like bethanechol, cisapride, domperidone and laxatives) may also reduce the effect of the antibiotic.


Use of Fosfinex with food, drink and alcohol
It is recommended to take the medicine on an empty stomach, either 1 hour before eating food or 2 hours after eating them, since this can delay the absorption of Fosfomycin trometamol.

Special warningsand precautions

  • Talk to your doctor or pharmacist before taking Fosfinex.
  •  Before beginning the treatment with Fosfinex, please take into consideration whether in the past you suffered from allergic reactions to Fosfomycin. 
  •  If 2 or 3 days after the treatment with Fosfinex some local symptoms persist, it does not mean a therapeutic failure, it could probably be a consequence of the inflammation process (see “How to take Fosfinex”).
  •  Food may delay oral absorption of Fosfomycin trometamol.