Dehydropeptidase is an enzyme found in the kidney and is responsible for degrading the antibioticimipenem. Cilastatin can therefore be combined intravenously with imipenem in order to protect it from dehydropeptidase and prolong its antibacterial effect. Imipenem alone is an effective antibiotic and can be given without the cilastatin. Cilastatin itself does not have antibiotic activity.
Another carbapenem, meropenem is resistant to dehydropeptidase; therefore, it can be given without cilastatin.