Pharmacology Q&A | Pharmacology
1. A nurse practitioner is explaining the difference between genetics and
genomics to a colleague. Which statement accurately describes genetics?
A) The molecular analysis of the entire genome of a species
B) The study of inherited traits and their variation in an individual
C) The total genetic composition of an organism or species
D) The study of influences on gene expression without changing DNA
sequence
Correct Answer: The study of inherited traits and their variation in an
individual
Rationale: Genetics focuses on the study of inherited traits and their
variation in an individual, examining specific genes and their effects.
Genomics refers to the total genetic composition of an organism or species,
while epigenetics is the study of influences on gene expression without
altering DNA sequence. Understanding this distinction is essential for
advanced practice nurses interpreting genetic testing and pharmacogenomic
data.
2. A patient asks why some medications work well for her friend but not for
her. The nurse practitioner's best response incorporates which concept?
A) Drug-drug interactions are the primary reason for medication variation
B) Genetic variations affect how individuals metabolize medications
C) Age and weight are the only factors that matter in drug response
D) Brand name medications work better than generic formulations
Correct Answer: Genetic variations affect how individuals metabolize
medications
,Rationale: Pharmacogenomics explains how genetic variations influence
individual responses to medications, including differences in metabolism,
efficacy, and adverse effects. While drug interactions, age, and weight do
affect drug response, genetic factors play a significant role in explaining
inter-individual variation. Brand and generic medications contain the same
active ingredients.
3. Cytochrome P450 enzymes are responsible for which primary function in
pharmacology?
A) Drug absorption from the gastrointestinal tract
B) Drug distribution to target tissues
C) Drug metabolism, primarily in the liver
D) Drug excretion through the kidneys
Correct Answer: Drug metabolism, primarily in the liver
Rationale: Cytochrome P450 enzymes are a family of enzymes primarily
located in the liver that metabolize medications, making them more water-
soluble for excretion. They do not directly mediate absorption, distribution, or
excretion. Genetic polymorphisms in CYP450 enzymes can significantly affect
drug metabolism and response.
4. A patient is prescribed warfarin and requires a lower-than-expected dose.
Genetic testing reveals a polymorphism in which enzyme system?
A) CYP2D6 and CYP3A4
B) CYP2C9 and VKORC1
C) CYP3A4 and P-glycoprotein
D) CYP1A2 and NAT2
Correct Answer: CYP2C9 and VKORC1
,Rationale: CYP2C9 metabolizes S-warfarin (the more active enantiomer), and
VKORC1 is the target enzyme (vitamin K epoxide reductase) inhibited by
warfarin. Genetic variants in both affect warfarin sensitivity and required
dosing. CYP2D6 affects many psychiatric drugs, and CYP3A4 and P-gp affect
many drugs including statins.
5. A patient with depression is prescribed a tricyclic antidepressant. The
patient develops significant side effects at a standard dose. Genetic testing
reveals the patient is a poor metabolizer of CYP2D6. What is the most likely
consequence?
A) The drug will be excreted more rapidly
B) The drug will accumulate to toxic levels
C) The drug will be less effective
D) The drug will be absorbed more slowly
Correct Answer: The drug will accumulate to toxic levels
Rationale: Poor metabolizers of CYP2D6 have reduced ability to metabolize
drugs that are substrates of this enzyme, leading to drug accumulation and
increased risk of toxicity. TCAs, many SSRIs, antipsychotics, and opioids are
metabolized by CYP2D6.
6. Which of the following is an example of an autosomal dominant disorder?
A) Cystic fibrosis
B) Sickle cell anemia
C) Huntington's disease
D) Tay-Sachs disease
Correct Answer: Huntington's disease
, Rationale: Huntington's disease is an autosomal dominant disorder, meaning
only one copy of the mutated gene is needed for disease expression. Cystic
fibrosis, sickle cell anemia, PKU, and Tay-Sachs are autosomal recessive
disorders.
7. Which of the following is an example of an X-linked recessive disorder?
A) Marfan syndrome
B) Duchenne muscular dystrophy
C) Fragile X syndrome
D) Huntington's disease
Correct Answer: Duchenne muscular dystrophy
Rationale: Duchenne muscular dystrophy is an X-linked recessive disorder.
Fragile X syndrome and Rett syndrome are examples of X-linked dominant
disorders. Marfan syndrome is autosomal dominant, and Huntington's
disease is autosomal dominant.
8. A female patient has a child with an X-linked recessive disorder. What is
the most likely genetic status of the patient?
A) She is homozygous affected
B) She is a carrier
C) She is unaffected and not a carrier
D) She has the disorder
Correct Answer: She is a carrier