Fosfomycin


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Acute uncomplicated UTI As fosfomycin tromethamine: 3 g as a single dose. IV Severe infections As fosfomycin disodium: Up to 20 g/day.
Dosage Details
Intravenous
Severe infections
Adult: As fosfomycin disodium: Up to 20 g daily.

Oral
Acute uncomplicated urinary tract infections
Adult: As fosfomycin tromethamine: 3 g (equivalent fosfomycin) as a single dose.
Renal Impairment
Acute uncomplicated urinary tract infections: No dosage adjustment needed.
Severe infections: Dosage adjustment needed.
Administration
Should be taken on an empty stomach. Take 1 hr before or 2 hr after meals.
Reconstitution
Oral powd: Dissolve the contents of a single-dose sachet containing 3 g of the drug in 90-120 mL of water. Do not use hot water. Powd for infusion: Dissolve 2 g and 8 g in 50 mL and 200 mL, respectively, using water for inj or glucose 5% or 10%.
Contraindications
Hypersensitivity to fosfomycin.
Special Precautions
Patient w/ cardiac insufficiency, HTN, hyperaldosteronism, hypernatraemia or pulmonary oedema. Renal impairment (IV). Pregnancy and lactation.
Adverse Reactions
GI disturbances (e.g. nausea, diarrhoea), transient increase in aminotransferase levels, headache, visual disturbances, skin rashes, eosinophilia, angioedema, aplastic anaemia, exacerbation of asthma, cholestatic jaundice, hepatic necrosis, toxic megacolon.
Potentially Fatal: Anaphylactic shock, antibiotic-associated colitis and pseudomembranous colitis.
Patient Counseling Information
Certain adverse effects may occur which may impair ability to drive or operate machinery.
MonitoringParameters
Monitor serum electrolyte levels and water balance; signs and symptoms of UTI.
Overdosage
Symptoms: Vestibular loss, impaired hearing, metallic taste, and general decline in taste perception. Management: Symptomatic and supportive treatment.
Drug Interactions
Additive or synergistic effect w/ β-lactam antibiotics (e.g. penicillin, ampicillin, cefazolin, carbapenems) and anti-staphylococcal agents (e.g. linezolid, quinupristin/dalfopristin, moxifloxacin). Reduced serum levels w/ drugs which increase GI motility (e.g. metoclopramide).
Action
Description: Fosfomycin exerts bactericidal effect on proliferating pathogens by preventing the enzymatic synthesis of the bacterial cell wall. It inhibits the 1st stage of intracellular bacterial cell wall synthesis by blocking peptidoglycan synthesis.
Pharmacokinetics:
Absorption: Rapidly absorbed from the GI tract (fosfomycin tromethamine). Time to peak plasma concentration: 4 hr. Bioavailability: Approx 30-40%.
Distribution: Widely distributed in body fluids including CSF and bile. Crosses the placenta and enters breast milk (small amounts). Volume of distribution: 0.3 L/kg.
Metabolism: Not metabolised by the liver.
Excretion: Via urine, as unchanged drug. Plasma half-life: Approx 2 hr.
Chemical Structure

Chemical Structure Image
Fosfomycin

Source: National Center for Biotechnology Information. PubChem Database. Fosfomycin, CID=446987, https://pubchem.ncbi.nlm.nih.gov/compound/Fosfomycin (accessed on Jan. 21, 2020)

Storage
Oral powd: Store at 25°C. Reconstituted soln for infusion: Store between 2-8°C; stable for 12 hr. Protect from light.
References
Anon. Fosfomycin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 16/10/2014.

Buckingham R (ed). Fosfomycin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com . Accessed 16/10/2014.

McEvoy GK, Snow EK, Miller J et al (eds). Fosfomycin Tromethamine. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com . Accessed 16/10/2014.

Monurol Powder (Forest Laboratories). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 16/10/2014.

Disclaimer: This information is independently developed by MIMS based on Fosfomycin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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