Fosfomycin blocks murein synthesis and thus cell wall construction of bacteria by inhibiting a specific enzyme. In the case of cystitis, it should be taken in the evening and water should be avoided until the next morning to allow the antibiotic to exert its full effect.
Oral bioavailability is 32 to 54%, intravenous administration is also possible. The effect usually lasts for more than 36 hours. Since it is excreted by the kidneys, dose reduction is required in cases of reduced renal function.
Synergistic effects may be achieved in combination with beta-lactam antibiotics, such as penicillins, cephalosporins, and carbapenems. Parallel medication with metoclopramide may reduce efficacy, so an interval of at least two to three hours should be maintained. In addition, the effect of vitamin K antagonists (e.g., Marcumar) is increased when fosfomycin is taken, which may lead to increased bleeding.