Posology : מינונים

4.2      Posology and method of administration
The daily dose of fosfomycin is determined based on the indication, severity and site of the infection, susceptibility of the pathogen(s) to fosfomycin and the renal function. In children, it is also determined by age and body weight.
Adults and adolescents (≥ 12 years of age) (≥ 40 kg):
The general dosage guidelines for adults and adolescents with estimated creatinine clearance > 80 ml/min are as follows:
Table 1 – dosing in adults and adolescents with CrCl >80 ml/min
Indication                                       Daily dose
Complicated urinary tract infection              12–24 g a in 2–3 divided doses Infective endocarditis                           12–24 g a in 2–3 divided doses Bone and joint infections                        12–24 g a in 2–3 divided doses Hospital-acquired pneumonia, including           12–24 g a in 2–3 divided doses ventilator-associated pneumonia
Complicated skin and soft tissue infections      12–24 g a in 2–3 divided doses Bacterial meningitis                             16–24 g a in 3–4 divided doses Complicated intra-abdominal infections           12–24 g a in 2–3 divided doses Bacteraemia that occurs in association with,     12–24 g a in 2–3 divided doses or is suspected to be associated with, any of the infections listed above
Individual doses must not exceed 8 g.
a
The high-dose regimen in 3 divided doses should be used in severe infections expected or known to be caused by less susceptible bacteria.
There are limited safety data in particular for doses in excess of 16 g/day. Special caution is advised when such doses are prescribed.
Duration of treatment
Treatment duration should take into account the type of infection, the severity of the infection as well as the patient's clinical response.
Elderly patients
The recommended doses for adults should be used in elderly patients. Caution is advised when considering the use of doses at the higher end of the recommended range (see also recommendations on dosage for patients with impaired renal function).
Renal impairment
No dose adjustment is recommended in patients within estimated creatinine clearance between 40–80 ml/min. However, caution should be exercised in these cases, particularly if doses at the higher end of the recommended range are considered
In patients with impaired renal function the dose of fosfomycin must be adjusted to the degree of renal impairment.
Dose titration should be based on creatinine clearance values.
Table 2 shows the recommended dose adjustments for patients with a CrCL less than 40 mL/min:
Table 2 – Dose adjustments for patients with a CrCL less than 40 mL/min CLCR patient    CLCR patient/CLCR normal      Daily dosage recommendeda 
    40 mL/min       0.333                            70% (in 2-3 divided doses)
30 mL/min       0.250                            60% (in 2-3 divided doses) 20 mL/min       0.167                            40% (in 2-3 divided doses)
10 mL/min       0.083                            20% (in 1-2 divided doses) a
The dose is expressed as a proportion of the dose that would have been considered appropriate if the patient's renal function were normal as calculated according to Cockgroft- Gault formula.
The first dose (loading dose) should be increased by 100%, but must not exceed 8 g.
Patients undergoing renal replacement therapy
Patients undergoing chronic intermittent dialysis (every 48 hours) should receive 2 g of fosfomycin at the end of each dialysis session.
During continuous veno-venous hemofiltration (post-dilution CVVHF), fosfomycin is effectively eliminated. Patients undergoing post-dilution CVVHF will not require any dose adjustment (see section 5.2).
Hepatic impairment
No dose adjustment is necessary in patients with hepatic impairment.
Paediatric population
Dose recommendations are based on very limited data.
Neonates, infants and children < 12 years of age (< 40 kg)
The dosage of fosfomycin in children should be based on age and body weight (BW): Table 3 – Dosing in children and neonates
Age/weight                                         Daily dose
Premature neonates (age a <40 weeks)               100 mg/kg BW in 2 divided doses Neonates (age a 40-44 weeks)                       200 mg/kg BW in 3 divided doses Infants 1-12 months (up to 10 kg BW)               200-300 b mg/kg BW in 3 divided doses
Infants and children aged 1≤12 years (10≤40 kg     200-400 b mg/kg BW in 3-4 divided BW)                                                doses a
Sum of gestational and postnatal age b
The high-dose regimen may be considered for severe infections and or serious infections (such as meningitis), in particular when known or suspected to be caused by organisms with moderate susceptibility.
No dose recommendations can be made for children with renal impairment.
Method of administration
Fomicyt is intended for intravenous use.
The duration of infusion should be at least 15 minutes for the 2 g pack size, at least 30 minutes for the 4 g pack size and at least 60 minutes for the 8 g pack size.

As damaging effects can result from inadvertent intra-arterial administration of products not specifically recommended for intra-arterial therapy, it is essential to ensure that fosfomycin is only administered into veins.
For instructions on reconstitution and dilution of the medicinal product before administration, see section 6.6.