Insignificant hepatic metabolism, no data pointing to CYP interaction; both components are mainly excreted in unchanged form in urine. To be observed: Tienam medication gives a mauve colour to the urine sample in the colorimetric PBG-assay, causing a false positive reaction!

Imipenem is a parenterally administered bata-lactam antibiotic of tienamycin type used in intraabdominal and acute gynaecological infections and pneumonia. Cilastatin is an enzyme inhibitor which inhibits the metabolism of imipenem in the kidneys. 70-80% of the imipenem as well as of cilastatin is excreted in urine in unchanged form. The rest of impenem is metabolized in the kidneys by splitting of the beta-lactamring. 10% of the cilastatin is excreted as the metabolite N-acetylcilastatin. South African list: no data/avoid Andersson: Occasionally used without side effects.