Pharmacodynamics
Like other of the ß-lactam antibiotics, pivmecillinam interferes with the biosynthesis of the bacterial cell wall in that the opened ß-lactam ring inhibits the enzyme D-alanine transpeptidase. The terminal alanine residues can now no longer combine with glycine, resulting in instabilization of the cell wall and thus killing the bacterium.
The multiplication of the bacteria is inhibited by the antibiotic binding to penicillin binding protein 2 (PBP 2). Since other penicillins and cephalosporins mainly bind only to PBP 1 and 3, cross-resistance rarely occurs.
Pharmacokinetics
Pivmecillinam is an inactive precursor of mecillinam, which is well absorbed orally and degraded in the intestinal mucosa to amdinocillin. Like other penicillins, the half-life is only about one hour. The antibiotic is excreted primarily by the kidney.
Interactions
Excretion of the antibiotic decreases with concomitant use with probenecid.
Pivmecillinam selbst reduziert die Ausscheidung des Zytostatikums Methotrexat.
Das Risiko eines Carnitinmangels erhöht sich bei gleichzeitiger Einnahme von Pivmecillinam mit Valproinsäure.