Fosfomycin

Product: Fomicyt 40 mg/ml powder for solution for infusion (UK SPC) - intravenous fosfomycin. Daily dose is determined by indication, severity and site of infection, susceptibility of the pathogen and renal function. Table 1 (CrCl >80 ml/min): complicated urinary tract infection, infective endocarditis, bone and joint infections, hospital-acquired pneumonia including ventilator-associated pneumonia, complicated skin and soft tissue infections, complicated intra-abdominal infections and associated bacteraemia all 12-24 g daily in 2-3 divided doses; bacterial meningitis 16-24 g daily in 3-4 divided doses. 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 and special caution is advised when such doses are prescribed. Duration should take into account type and severity of infection and clinical response. Elderly: use the recommended adult doses, with caution at the higher end of the range. Hepatic impairment: no dose adjustment necessary. Administration: intravenous use only; infusion duration at least 15 minutes for the 2 g pack, at least 30 minutes for the 4 g pack and at least 60 minutes for the 8 g pack; ensure administration into veins only. High sodium content (0.32 g sodium per gram of fosfomycin) - monitor sodium and potassium and consider potassium supplementation. Whenever possible give as part of a combination antibacterial regimen (rapid selection of resistant mutants). SPC section 4.5 (interactions) was not captured in the fetched bundle. Separately, the US label in the bundle is a different product and route - fosfomycin tromethamine granules for ORAL solution, one single-dose sachet for uncomplicated urinary tract infection (acute cystitis) in women 18 years and older, mixed in 3-4 ounces of water (the sachet strength is not stated in the fetched text); do not apply the intravenous doses above to the oral sachet or vice versa.

SPC states dose recommendations are based on very limited data. Neonates, infants and children <12 years (<40 kg), dosing by age and body weight (BW): premature neonates (sum of gestational and postnatal age <40 weeks) 100 mg/kg BW daily in 2 divided doses; neonates (age 40-44 weeks) 200 mg/kg BW daily in 3 divided doses; infants 1-12 months (up to 10 kg BW) 200-300 mg/kg BW daily in 3 divided doses; infants and children aged 1 to <=12 years (10 to <=40 kg BW) 200-400 mg/kg BW daily in 3-4 divided doses. The high-dose regimen may be considered for severe 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. Adolescents >=12 years and >=40 kg use the adult regimen. Neonates under sodium restriction: assess the risk of hypernatraemia and fluid overload before starting. Verify against a children's formulary.