Question

What would be the patient’s response to a normal drug dose that because of a genetic variation in an enzyme that prepares the drug for elimination results in a blood drug level that is below the minimum effective concentration (MEC)?

Answer 1

The intended response fails to be produced.*In order for a drug to produce its intended response, its blood levels must reach the minimum effective concentration. When enzymes responsible for metabolizing and preparing drugs for elimination are more active as a result of a genetic variation, sensitive drugs are eliminated more rapidly, and a "normal" dose may not be high enough to allow the drug to be retained long enough to reach the MEC.