Q.1 Pharmacogenetics primarily studies:
The influence of diet on drug metabolism
Genetic factors affecting individual responses to drugs
Drug interactions in polypharmacy
The chemical structure of drugs
Explanation - Pharmacogenetics examines how variations in genes influence the efficacy and toxicity of drugs in individuals.
Correct answer is: Genetic factors affecting individual responses to drugs
Q.2 Which enzyme is commonly associated with variations affecting drug metabolism?
Cytochrome P450
Lactase
Amylase
DNA polymerase
Explanation - Cytochrome P450 enzymes metabolize many drugs, and genetic variations can result in poor, intermediate, or ultra-rapid metabolism.
Correct answer is: Cytochrome P450
Q.3 A poor metabolizer of a drug may experience:
Reduced drug toxicity
Increased drug efficacy
Drug accumulation and toxicity
No effect on drug response
Explanation - Poor metabolizers process drugs slowly, which can lead to higher plasma levels and increased risk of adverse effects.
Correct answer is: Drug accumulation and toxicity
Q.4 Which genetic variation is most commonly studied in pharmacogenetics?
Single nucleotide polymorphisms (SNPs)
Chromosomal translocations
Copy number variations in mitochondria
Telomere shortening
Explanation - SNPs are the most common genetic variations affecting drug metabolism and response in pharmacogenetics.
Correct answer is: Single nucleotide polymorphisms (SNPs)
Q.5 The gene TPMT is important in metabolizing which type of drug?
Thiopurines
Statins
Beta-blockers
NSAIDs
Explanation - Thiopurine methyltransferase (TPMT) metabolizes thiopurines. TPMT deficiency can cause drug toxicity.
Correct answer is: Thiopurines
Q.6 Which phenotype results from ultra-rapid metabolism of a drug?
Increased drug efficacy
Decreased drug effect
Drug toxicity
No drug metabolism
Explanation - Ultra-rapid metabolizers process drugs too quickly, reducing therapeutic effect because drug levels do not reach therapeutic concentration.
Correct answer is: Decreased drug effect
Q.7 Pharmacogenetic testing before prescribing drugs is most important for:
Drugs with a narrow therapeutic index
All over-the-counter drugs
Drugs with mild side effects
Topical medications only
Explanation - Drugs with narrow therapeutic index have a small window between efficacy and toxicity, so genetic testing helps in dose optimization.
Correct answer is: Drugs with a narrow therapeutic index
Q.8 CYP2D6 polymorphism affects the metabolism of:
Codeine and antidepressants
Insulin
Warfarin only
Penicillin
Explanation - CYP2D6 metabolizes codeine to morphine and also processes many antidepressants. Variants affect drug response significantly.
Correct answer is: Codeine and antidepressants
Q.9 Which term describes the study of the effect of an individual’s entire genome on drug response?
Pharmacogenomics
Pharmacokinetics
Pharmacodynamics
Toxicogenomics
Explanation - Pharmacogenomics studies the genome-wide impact on drug response, while pharmacogenetics focuses on single or few genes.
Correct answer is: Pharmacogenomics
Q.10 Abacavir hypersensitivity is strongly associated with which genetic marker?
HLA-B*57:01
CYP3A4
G6PD deficiency
TPMT mutation
Explanation - Patients carrying HLA-B*57:01 are at high risk of hypersensitivity to abacavir, an antiretroviral drug.
Correct answer is: HLA-B*57:01
Q.11 Warfarin dosing is influenced by variants in:
VKORC1 and CYP2C9 genes
BRCA1 and BRCA2 genes
HLA genes
TPMT gene
Explanation - Variants in VKORC1 (warfarin target) and CYP2C9 (metabolizing enzyme) significantly affect dose requirements and bleeding risk.
Correct answer is: VKORC1 and CYP2C9 genes
Q.12 Which is an example of a prodrug affected by pharmacogenetics?
Codeine
Aspirin
Metformin
Ibuprofen
Explanation - Codeine is converted to its active form, morphine, by CYP2D6. Genetic variations affect the conversion rate and efficacy.
Correct answer is: Codeine
Q.13 The term 'pharmacokinetics' refers to:
How the body absorbs, distributes, metabolizes, and excretes drugs
The mechanism of drug action on target cells
Genetic variations affecting drug response
Drug-drug interactions only
Explanation - Pharmacokinetics studies the fate of drugs in the body, which is influenced by genetic differences in metabolizing enzymes.
Correct answer is: How the body absorbs, distributes, metabolizes, and excretes drugs
Q.14 Which of the following drugs is affected by CYP2C19 polymorphism?
Clopidogrel
Penicillin
Metformin
Atenolol
Explanation - CYP2C19 metabolizes clopidogrel into its active form; poor metabolizers may have reduced antiplatelet effect.
Correct answer is: Clopidogrel
Q.15 The study of genetic variation in drug targets is called:
Pharmacodynamic pharmacogenetics
Pharmacokinetic pharmacogenetics
Toxicogenomics
Clinical pharmacology
Explanation - Pharmacodynamic pharmacogenetics focuses on how genetic differences in drug targets (receptors, enzymes) influence drug response.
Correct answer is: Pharmacodynamic pharmacogenetics
Q.16 G6PD deficiency affects the use of which type of drugs?
Oxidative drugs like primaquine
Beta-blockers
NSAIDs only
Statins
Explanation - G6PD-deficient individuals are at risk of hemolysis when exposed to oxidative drugs.
Correct answer is: Oxidative drugs like primaquine
Q.17 Which term describes drugs that require metabolic activation to become effective?
Prodrugs
Active drugs
Inert drugs
Biologics
Explanation - Prodrugs are inactive until metabolized, and genetic variations in metabolizing enzymes can alter their effect.
Correct answer is: Prodrugs
Q.18 Pharmacogenetic variability is most likely due to:
Polymorphisms in drug-metabolizing enzymes
Dietary habits only
Environmental pollutants
Age and sex alone
Explanation - Genetic polymorphisms in enzymes like CYP450 family significantly influence drug metabolism and response.
Correct answer is: Polymorphisms in drug-metabolizing enzymes
Q.19 Carriers of the HLA-B*15:02 allele are at risk of severe reactions with:
Carbamazepine
Warfarin
Clopidogrel
Ibuprofen
Explanation - HLA-B*15:02 is associated with Stevens-Johnson syndrome and toxic epidermal necrolysis in patients taking carbamazepine.
Correct answer is: Carbamazepine
Q.20 Which of the following best represents the goal of pharmacogenetics?
Personalized drug therapy based on genetic makeup
Developing new antibiotics
Understanding chemical drug synthesis
Measuring drug prices
Explanation - Pharmacogenetics aims to tailor drug type and dose to an individual's genetic profile for better efficacy and safety.
Correct answer is: Personalized drug therapy based on genetic makeup
Q.21 Which of the following statements is TRUE about ultra-rapid metabolizers?
They may require higher doses to achieve therapeutic effect
They accumulate drugs leading to toxicity
They are resistant to all medications
Their metabolism is identical to normal metabolizers
Explanation - Ultra-rapid metabolizers process drugs quickly, often requiring increased dosing for efficacy.
Correct answer is: They may require higher doses to achieve therapeutic effect
Q.22 Pharmacogenetic testing is NOT routinely required for:
Acetaminophen in normal doses
Abacavir
Warfarin
Clopidogrel
Explanation - Acetaminophen is metabolized safely in most individuals; genetic testing is usually unnecessary, unlike drugs with narrow therapeutic index or severe hypersensitivity risks.
Correct answer is: Acetaminophen in normal doses
Q.23 Which is a challenge in implementing pharmacogenetics in clinical practice?
High cost and limited availability of genetic testing
Lack of drugs
Excessive drug manufacturing
Patient noncompliance only
Explanation - While pharmacogenetics can improve therapy, high costs and testing availability remain barriers.
Correct answer is: High cost and limited availability of genetic testing
Q.24 Which CYP enzyme is crucial for metabolizing many antidepressants?
CYP2D6
CYP1A2
CYP3A4
CYP2C9
Explanation - CYP2D6 metabolizes several antidepressants and other CNS drugs; genetic variants can significantly affect plasma levels.
Correct answer is: CYP2D6
Q.25 The term 'phenoconversion' in pharmacogenetics refers to:
Environmentally induced changes in drug metabolism phenotype
Permanent genetic mutations
Drug design process
Measurement of drug half-life
Explanation - Phenoconversion occurs when environmental factors or drug interactions temporarily alter the metabolic phenotype, despite genotype.
Correct answer is: Environmentally induced changes in drug metabolism phenotype