Monuril Mechanism of Action

Pharmacology: Pharmacodynamics: Fosfomycin is a bactericidal antibiotic with a rather broad spectrum. It is bactericidal by inhibiting the enzyme enolpyruviltransferase, which is involved in the synthesis of the bacterial cell wall. The use of a single dose of fosfomycin reduces the risk of resistance. Monuril has no negative influence on the intestinal flora.
Microbiology: Fosfomycin is active against gram-positive (S. faecalis) and gram-negative microorganisms (E. coli, Proteus). Resistance is observed for Klebsiella, Enterobacter, Serratia and Pseudomonas. Cross-resistance with other antibiotics is not reported. For the breakpoint, MIC 128 mg/L is usually taken. (See table.)


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Pharmacokinetics: Fosfomycin is moderately absorbed after oral administration of Monuril. The absolute bioavailability is 30-55%. The peak serum concentration is attained after 2-3 hrs and amounts to 30-45 mcg/mL after administration of 50 mg/kg. After administration of a single dose of fosfomycin 50 mg/kg body weight, therapeutically active concentration in urine is maintained for 36 hrs.
Fosfomycin is not bound to plasma protein. Tissue penetration is good. The apparent volume of distribution is about 22 L.
The elimination half-life is 2.5-7 hrs. Fosfomycin is excreted in the urine by glomerular filtration. In patients with renal insufficiency, excretion is reduced and serum elimination half-life is prolonged. After oral administration, 35-50% is excreted in the urine. Urinary excretion decreases along with the decrease in renal function. Fosfomycin is not metabolized.