Is fosfomycin safe for the liver?

Fosfomycin Liver Safety Profile

Fosfomycin is generally safe for the liver and does not require dose modification in patients with hepatic impairment. 1

Pharmacokinetics and Hepatic Metabolism

• Fosfomycin has a low molecular weight (138 Da) and is not structurally associated with other classes of antibiotics 1
• The drug does not undergo enterohepatic circulation, meaning dose modification is not required in patients with hepatic impairment 1
• Fosfomycin is primarily cleared via the kidneys rather than through hepatic metabolism 1, 2

Safety Profile

• According to FDA labeling, liver-related adverse events from fosfomycin are rare 3
• Post-marketing surveillance has reported rare cases of cholestatic jaundice and hepatic necrosis, although causality has not been established 3
• Laboratory changes observed in clinical trials include occasional increases in bilirubin, SGPT (ALT), SGOT (AST), and alkaline phosphatase, but these changes were generally transient and not clinically significant 3

Monitoring Recommendations

• Routine liver function monitoring is not specifically required for fosfomycin administration in patients with normal liver function 3
• For patients with underlying liver disease, laboratory monitoring should be considered, although specific guidelines for fosfomycin are limited 4

Advantages in Special Populations

• Fosfomycin has extensive tissue penetration, making it suitable for various infection sites including soft tissues, bone, lungs, and abscesses 1, 2
• The drug has gained renewed interest for treating serious systemic infections caused by multidrug-resistant bacteria 1

Clinical Applications

• Oral fosfomycin (fosfomycin tromethamine) is primarily used for urinary tract infections as a single 3-gram dose 2, 5
• Intravenous fosfomycin has been used in combination with other antibiotics for treating nosocomial infections due to multidrug-resistant bacteria 5

Precautions

• While fosfomycin itself appears to have minimal hepatotoxic potential, caution should be exercised when using any antimicrobial agent in patients with severe liver disease 4
• When treating patients with underlying liver disease, clinical and biochemical monitoring is generally recommended as a precautionary measure 4

Comparison to Other Antibiotics

• Unlike some antibiotics such as certain antituberculosis drugs that carry specific warnings about use in liver disease, fosfomycin does not have such restrictions 4
• Fosfomycin may be a safer alternative to antibiotics with known hepatotoxic potential in patients with liver disease 1, 5