- fosfomycin trometamol
POM: Prescription only medicine
This information is intended for use by health professionals
AdultsUncomplicated lower urinary tract infections: one sachet (3g) Perioperative prophylaxis of urinary tract infections: one 3g sachet 3 hours before the procedure
Paediatric populationFosfomycin trometamol in a dose of 3g is not suitable for children under the age of 12 years.
Method of administrationFosfomycin is for oral administration and should be taken on an empty stomach, either 1 hour before or at least 2 hours after meals and preferably before bedtime after emptying the bladder. The contents of a sachet should be dissolved in a glass of water and taken immediately after its preparation.For instructions on reconstitution of the medicinal product before administration, see section 6.6.
Older people and Patients with Renal ImpairmentFosfomycin trometamol is principally excreted by the kidney. Caution should be exercised in administering this antibiotic to patients with impaired renal function (see section 5.2).Antibiotic associated colitis (incl. pseudomembranous colitis) has been reported in association with the use of broad spectrum antibiotics including fosfomycin trometamol; therefore it is important to consider this diagnosis in patients who develop serious diarrhoea during or after the use of fosfomycin trometamol. In this situation adequate therapeutic measures should be initiated immediately. Drugs inhibiting peristalsis are contraindicated in this situation. This medicine contains 1,923 g of sucrose per sachet. Patients with rare hereditary problems of fructose intolerance, glucose - galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.
PregnancyThere are limited data from the use of fosfomycin in pregnant women. Animal studies with fosfomycin trometamol (the form used in Fosfomycin) have shown no hazard to the fetus.Previous studies in the rat showed fetal toxicity following administration of the calcium and sodium salts of fosfomycin at the maximum doses tested (approximately 25 times the therapeutic dose). However, toxicity to the foetus was not observed at lower doses in the rat or at any of the doses tested in the rabbit. Fosfomycin should only be used in pregnancy when the expected benefits outweigh the risk.
Breast-feedingFosfomycin is excreted in breast milk. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Fosfomycin therapy taking into account the benefit of breast-feeding for the child and the benefit of therapy for the woman.
FertilityNo clinical data are available; hence the potential risk for humans is unknown.
|Very common: Common: Uncommon: Rare: Very rare:Not known:||(≥1/10) (≥1/100 to <1/10) (≥1/1,000 to <1/100) (≥1/10,000 to <1/1,000) (<1/10,000) (cannot be estimated from the available data)|
|Immune system disorders|
|Not known||anaphylactic shock allergic reaction|
|Nervous system disorder|
|Respiratory, thoracic and mediastinal disorders|
|Uncommon||diarrhoea nausea vomiting abdominal pain|
|Not known||pseudomembranous colitis|
|Skin and subcutaneous tissue disorders|
|Uncommon||rash urticaria pruritus|
|Reproductive system and breast disorders|
|General disorders and administration site conditions|
Reporting of suspected adverse reactionsReporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme at www.mhra.gov.uk/yellowcard..
Mechanism of actionFosfomycin trometamol is a broad spectrum antibiotic, derived from phosphonic acid.It inhibits the enzyme phosphoenolpyruvate transferase, which catalyses the formation of n-acetylmuramic acid from n-acetyl aminoglucose and phosphoenolpyruvate. N-acetylmuramic acid is required for the build-up of peptidoglycan, an essential component of the bacterial cell wall. Fosfomycin has a mainly bactericidal action.
PK/PD relationshipLimited data indicate that fosfomycin most likely acts in a time- dependent manner.
Mechanisms of resistanceA resistance to fosfomycin can be based on the following mechanisms:• Fosfomycin is admitted into the bacterial cell actively via two different transport systems (glycerin-3-phosphate and hexose-6 transport system). In Enterobacteriaceae the glycerin-3-phosphate transport system can be changed in such a way that fosfomycin is no longer transported into the cell.• Another plasmid-encoded mechanism occurring in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp. is based on the presence of a specific protein, under the effect of which fosfomycin metabolises and is bound to glutathione (GSH).• In staphylococci a plasmid-encoded fosfomycin resistance also occurs. The exact mechanism of the resistance has not yet been determined.A cross-resistance of fosfomycin with other antibiotics classes is not known.
Break pointsEUCAST clinical MIC breakpoints for oral fosfomycin to separate susceptible (S) pathogens from resistant (R) pathogens are: • Enterobacteriaceae S≤32mcg/ml, R>32mcg/ml
SusceptibilityThe prevalence of the acquired resistance of individual species can vary locally and in the course of time. Local information on the resistance situation is therefore required particularly for the adequate treatment of severe infections. If the effectiveness of fosfomycin is doubtful due to the local resistance situation, a therapy consultation by experts is recommended. Particularly in the case of serious infection or therapy failure, a microbiological diagnosis indicating the pathogen and its sensitivity to fosfomycin is recommended.The information below gives only approximate guidance on the probability as to whether the micro-organism will be susceptible to fosfomycine or not.
|Commonly susceptible species:|
|Species for which acquired resistance may be a problem:|
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