Question

Pharmacogenetics is the study of the effects of genetic factors on drug responses in patients. Interindividual differences in the sequences of genes that encode the drug’s molecular target or transporters, or the enzymes responsible for drug metabolism, can profoundly affect the success or failure of a drug or therapeutic. Which of the following genetic variations would NOT lead to pharmacodynamic variation?

a) Genetic variation leading to altered activity of enzymes involved in drug metabolism.
b) Genetic variation leading to altered expression of the drug’s molecular target.
c) Genetic variation leading to decreased affinity of a drug for a receptor.
d) Genetic variation leading to altered downstream signaling

Answer 1

Genetic variation leading to altered activity of enzymes involved in drug metabolism does not lead to pharmacodynamic variation but rather affects the pharmacokinetics of the drug.

Step-by-step explanation:

Pharmacogenetics is the study of the effects of genetic factors on drug responses in patients. When considering pharmacodynamic variation, this deals with how the drug interacts with its biological target, affecting the drug's efficacy and potential side effects. Genetic variation that would not lead to pharmacodynamic variation is:

• a) Genetic variation leading to altered activity of enzymes involved in drug metabolism.

This is because such variations affect the pharmacokinetics of a drug, i.e., how the body processes the drug, rather than the pharmacodynamics (drug's action on the body). Variations that affect pharmacodynamics include, but are not limited to, altered expression of the drug's molecular target, decreased affinity of a drug for a receptor, and changes in downstream signaling pathways.