Fosfomycin

Updated: 2026-09-18

Overview

Fosfomycin is a broad-spectrum antibiotic discovered in the 1960s, primarily used to treat bacterial infections, especially urinary tract infections (UTIs). It is derived from phosphonic acid and is known for its unique mechanism of action, which involves inhibiting the early stages of bacterial cell wall synthesis. Fosfomycin is available in various forms, including oral tablets, granules, and intravenous solutions. Its efficacy against a wide range of Gram-positive and Gram-negative bacteria makes it a valuable tool in clinical settings, particularly for uncomplicated UTIs.

Physical and Chemical Properties

Fosfomycin is a white to off-white crystalline powder with a molecular weight of 138.06 g/mol. It is soluble in water and slightly soluble in ethanol. The compound has a melting point of approximately 94-97°C and is stable under recommended storage conditions. Its molecular formula, C3H7O4P, reflects its phosphonic acid derivative structure. The compound’s stability in solid form and solubility profile make it suitable for various pharmaceutical formulations, including oral and injectable preparations.

Main Applications

Fosfomycin is primarily used to treat urinary tract infections (UTIs), including bacterial cystitis. Its broad-spectrum activity covers common pathogens such as Escherichia coli, Enterococcus faecalis, and Klebsiella pneumoniae. In addition to UTIs, fosfomycin is sometimes used off-label for other bacterial infections, particularly in cases where resistance to other antibiotics is a concern. Its unique mechanism of action reduces the likelihood of cross-resistance with other antibiotic classes.

Safety and Storage

Fosfomycin should be stored in a cool, dry place below 25°C, protected from light and moisture. Proper storage ensures the stability and efficacy of the compound over time. Safety precautions include monitoring patients for gastrointestinal side effects, such as diarrhea and nausea. Use with caution in patients with renal impairment, as dosage adjustments may be necessary. Always follow clinical guidelines for administration.

B2B Procurement Guide

When procuring fosfomycin, verify the CAS number (23155-02-4) and purity specifications to ensure product quality. Suppliers should comply with Good Manufacturing Practices (GMP) to guarantee consistency and safety. Prices typically range from approximately $50 to $200 per kilogram, depending on purity and supplier. Bulk buyers should request certificates of analysis (CoA) and consider long-term supply agreements to secure stable pricing.