Ultrarapid Information and Courses from MediaLab, Inc.

When discussing PGx, we classify a person according to his/her phenotype (metabolic capacity for a given enzyme).A poor metabolizer (PM) is a person who lacks the functional enzyme and therefore exhibits decreased metabolism of drugs. This person would require lower doses of a drug that is metabolized by that enzyme. A PM who receives a standard dose is more likely to experience unwanted side effects or toxicity. A PM can also experience diminished effects with drugs that need to be metabolized to active compounds by the enzyme in question.An ultrarapid metabolizer (UM) will require a higher dose than usual since he/she will eliminate the drug more quickly. A UM may be resistant to standard treatments, and it may take some time to adjust the dosage before therapy is achieved.An intermediate metabolizer (IM) has one wild-type (normal) copy of the gene and one absent or dysfunctional copy. The IM group is very heterogeneous.A person with normal enzyme activity is referred to as an extensive metabolizer (EM). This person should respond to standard dosages of a drug. Most people are EM's. This is the population in which most dosing regimens have been worked out in clinical trials.