FOSFOMYCIN TROMETHAMINE Drug Interactions: What You Need to Know

Drug Interactions Metoclopramide: When coadministered with fosfomycin tromethamine granules for oral solution, metoclopramide, a drug which increases gastrointestinal motility, lowers the serum concentration and urinary excretion of fosfomycin. Other drugs that increase gastrointestinal motility may produce similar effects. Cimetidine: Cimetidine does not affect the pharmacokinetics of fosfomycin when coadministered with fosfomycin tromethamine granules for oral solution.

CONTRAINDICATIONS Fosfomycin tromethamine granules for oral solution is contraindicated in patients with known hypersensitivity to the drug.

WARNINGS Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including fosfomycin tromethamine granules for oral solution, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.