Analysis of oral fosfomycin calcium (Fosmicin) side-effects after marketing.

For about 6 years after the marketing of oral formulations of fosfomycin calcium (FOM-Ca) in December, 1980, we collected the data on 35,481 cases and analyzed it regarding safety. Primary side-effects consisted mainly in gastrointestinal disturbances, damage to skin and adnexa, liver and bile duct disorders. Specifically, diarrhea, nausea, abdominal pain, anorexia, eruption and increased serum transaminase were frequent. Serious and newly detected side-effects after marketing were pseudomembranous colitis and melena, one case each. As for the oral administration of FOM-Ca to 83 patients hypertensive to beta-lactams, gastrointestinal side-effects were seen but none of them developed hypersensitivity, an allergic reaction.