Patent ID: 7094558

Claim:
A method of determining the presence of an active angiotensin converting enzyme (ACE)-inhibiting drug present in a fluid sample, said ACE-inhibiting drug in its active state modifying the activity level of ACE on a substrate, wherein said substrate is specific for ACE, said method comprising the steps of: providing a first fluid sample obtained from a patient that may contain any of said ACE-inhibiting drug, said first fluid sample being a serum or urine sample and including ACE; adding a quantity of said substrate to said first fluid sample; measuring the activity level of ACE on said substrate; comparing said measured activity level with a standard activity level established by testing serum or urine samples from a plurality of individuals other than the patient that have a known quantity of active ACE-inhibiting drug present; and determining the presence of said active ACE-inhibiting drug by the measured activity level compared to said standard activity level.