old mult. choice questions Flashcards
Drug induced liver injury is a significant problem for many drugs already in clinical use, as well as new drugs under development Which of the following efflux transporters is most often involved in drug-induced cholestasis?
a. P-glycoprotein
b. multi drug resistance associated protein
c. breast cancer resistance protein
d. organic anion transporting polypeptide
e. bile salt export protein
e. bile salt export protein
Which one of the following cytochrome P-450 enzymes plays the most prominent role in first pass metabolism drugs? a. CYP 1A2 b. CYP 2D6 c. CYP 2E! d. CYP 3A4 e. CYP 2C19
d. CYP 3A4
Quinidine interacts with digoxin by which of the following mechanism?
a. inhibition of CYP 2D6
b. inhibition of P-glycoprotein
c. inhibition of CYP 3A4
d. induction of P-glycoprotein
e. induction of CYP 2D6
b. inhibition of P-glycoprotein
An individual who is overly sensitive to the effects of codeine may result from:
a. expression of a a non synonymous CYP 2D6 SNP
b. expression of a synonymous CYP 2D6 SNP
c. expression of multiple copies of the CYP 2D6 gene
d. a deletion in the CYP 2D6 gene
e. expression of a non synonymous CYP 2C9 SNP
c. expression of multiple copies of the CYP 2D6 gene
Rifampin induces the effectiveness of oral contraceptives by which of the following?
a. induction of CYP 1A2
b. induction of CYP 3A4
c. induction of CYP 2C9
d. induction of OATP
e. Induction of P-gp
b. induction of CYP 3A4
Which of the following SSRI’s are adversely affected by induction of CYP 2D6?
a. fluoxetine
b. paroxetine
c. citalopram
d. fluvoxamine
e. all of the above
f. none of the above
f. none of the above – There are no known inducers of CYP 2D6
Which of the following nuclear receptors is responsible for up regulating transcription of the CYP 3A4 gene? a. steroid xenobiotic receptor b. farnesoid X receptor c. constitutive androstane receptor d aryl hydrocarbon receptor e. vitamin E receptor
a. steroid xenobiotic receptor
Transplant recipients immunosuppressed with cyclosporine are at risk for graft rejection when ingesting which herbal supplement?
a. ginseng
b. St. John’s wort
c. echinacea
d. saw palmetto
e. ginkgo biloba
b. St. John’s wort
Which of the following statements is true regarding the interaction between penicillin and probenecid?
a. probenecid reduces the hepatic clearance of penicillin
b. probenecid decreases the half life of penicillin
c. probenecid increases the renal clearance of penicillin
d. probenecid inhibits the renal uptake transporter OAT
e. probenecid inhibits CYP 1A2
d. probenecid inhibits the renal uptake transporter OAT
Fruit juices can often affect the bioavailability of drugs when ingested concomitantly. Which combination of juice and drug will result in an increase in oral bioavailability?
a. grapefruit juice and felodipine
b. grapefruit juice and chlorzoxazone
c. orange juice and fexofenadine
d. orange juice and caffeine
e. cranberry juice and midazolam
a. grapefruit juice and felodipine
A patient has been receiving codeine for pain after tooth extraction is not experiencing any therapeutic benefit (i.e. pain relief). If this patient;s lack of response is because of an inability to metabolize codeine to the active moiety morphine, a homozygous genetic mutation in which one of the following genes is most likely responsible?
a. CYP 1A2
b. CYP 2C9
c. CYP 2D6
d. CYP 2C19
e. CYP 3A4
c. CYP 2D6
Grapefruit juice will significantly increase the oral bioavailability of which of the following drugs?
a. indinavir (CYP 3A4 substrate, F=0.8)
b. quinidine (CYP 3A4/P-gp substrate, F=0.8)
c. fexofenadine (OATP substrate, F=0.2)
d. nisoldipine (CYP 3A4 substrate, F=0.1)
e. amlodipine (CYP 3A4 substrate, F=0.7)
d. nisoldipine (CYP 3A4 substrate, F=0.1)
A patient with DVT is being treated with warfarin at a standard dose of 5 mg/day. One week later, the patient presents with an intracerebral hemorrhage and the international normalized ratio is 11. The patient is genotyped and found to have a genetic mutation in the enzyme responsible for the metabolism of S-warfarin. The pharmacogenetics of which one of the following enzymes has been associated with adverse clinical outcomes and warfarin maintenance dose requirements?
a. CYP 1A2
b. CYP 2C9
c. CYP 2D6
d. CYP 3A4
e. CYP 2C19
b. CYP 2C9
Which one of the following transporters plays the most prominent role in first pass drug elimination?
a. OATP
b. OCTP
c. MRP2
d. BSEP
e. P-gp
e. P-gp
What effect does rifampin have on the pharmacokinetics of drugs whose metabolism is predominantly mediated by CYP 2D6?
a. has little effect on unbound steady state concentrations
b. significantly increases unbound stead state concentration
c. significantly decreases unbound steady state concentrations
d. significantly increases elimination half life
e. significantly decreases hepatic blood flow
a. has little effect on unbound steady state concentrations
A renal transplant patient receiving tacrolimus (CYP 3A4/P-gp substrate) for immunosuppression develops a systemic Candida albicans infection. Which of the following azalea antifungals is least likely to produce elected levels of tacrolimus and subsequent nephrotoxicity?
a. fluconazole
b. ketoconazole
c. itraconazole
d. miconazole
e. voriconazole
a. fluconazole
Which SSRI is associated with the fewest number of significant drug interactions?
a. citalopram
b. fluvoxamine
c. fluoxetine
d. paroxetine
e. venlafaxine
a. Citalopram
In general, which of the following pharmacokinetic parameters has the least impact on average unbound steady state concentrations?
a. clearance
b. bioavailability
c. dose
d. plasma protein binding
e. apparent volume of distribution
e. apparent volume of distribution
- Individuals homozygous for the CYP 2D6*3 allele will likely exhibit toxicity after chronic dosing of which of the following drugs?
a. quinidine
b. amitriptyline
c. codeine
d. warfarin
e. phenytoin
b. amitriptyline
- Which of the following is not an inhibitor of CYP 2D6?
a. quinidine
b. fluoxetine
c. paroxetine
d. amiodarone
e. fluvoxamine
e. fluvoxamine
- Chronic induction of which of the following CYPs is associated with an increased risk of carcinogenesis?
a. CYP 2D6
b. CYP 3A4
c. CYP 2E1
d. CYP 1A2
c. CYP 2E1
Is obesity more likely to induce or inhibit CYP 3A4 metabolism?
inhibit
For the following drug classes, give one example of a “safe choice” drug that has less potential for affecting the metabolism of other drugs:
1 A safe choice for a macrolide antibiotic:
2 A safe choice for an H2 blocker:
3 A safe choice for an HMG CoA Reductase Inhibitor:
azithromycin
famotidine
fluvastatin
Each of the following drugs may interfere with cyclosporine except:
a. erythromycin
b. verapamil
c. St. John’s wort
d. caffeine
e. intraconazole
d. caffeine
For which of the following CYP’s is polymorphism a very important consideration?
a. CYP 1A2
b. CYP 2E1
c. CYP 3A4
d. CYP 4A3
b. CYP 2E1
Each of the following inhibits CYP 3A4 except:
a. introconazole
b. phenytoin
c. cimetidine
d. ritonavir
e. clarithyromycin
b. phenytoin
The least important mechanism for drug interactions is
a. displacement from plasma proteins
b. competitive inhibition of CYP 3A4
c. reduced metabolic clearance
d. reduced renal elimination
e. induction of P-gp
a. displacement from plasma proteins
If the metabolism of a drug is impeded because of enzyme inhibition, each of the following may result except:
a. a high plasma drug level
b. enhancement of the drug’s therapeutic effect
c. minimization of undesirable side effects of the drug
d. enhanced importance of alternative metabolic pathways
e. reduced therapeutic efficacy of a prodrug
c. minimization of undesirable side effects of the drug
Each of the following is a P-gp substrate except:
a. midazolam
b. digoxin
c. cyclosporine
d. timolol
e. vinblastine
a. midazolam– 3A4 substrate
Each of the following is true regarding polymorphisms except:
a. genetic polymorphism means that, within a normal population, some people have a functional enzyme, whereas others do not
b. there are no ethnic differences with regard to population distribution of genetic polymorphisms
c. people with genetically determined low levels of activity are referred to as poor metabolizers
d. people who have a functional enzyme are known as extensive metabolizers
e. poor metabolizers may be at a greater risk of toxicity than extensive metabolizers for drugs that are highly dependent on clearance to an inactive metabolite
b. there are no ethnic differences with regard to population distribution of genetic polymorphisms
The following botanical supplements can result in herb/drug interactions except:
a. St. John’s wort
b. Ginkgo biloba
c. goldenseal
d. Panax ginseng
e. saw palmetto
e. saw palmetto
A poor metabolizer phenotype is not likely to affect which of the following drugs?
a. codeine
b. tolbutamide
c. warfarin
d. erythromycin
e. omeprazol
d. erythromycin
Which of the following CYP’s is least important with regard to drug interactions?
a. CYP 1A2
b. CYP 2E1
c. CYP 2D6
d. CYP 3A4
e. CYP 2C9
b. CYP 2E1
- CYP 3A4 inhibitors are likely to cause the most dramatic increases in plasma drug levels of orally administered drugs which are CYP 3A4 substrates with these drugs:
a. have low inherent oral bioavailability
b. have high inherent oral bioavailability
c. are renal excreted
d. are excreted in the bile
a. have low inherent oral bioavailability
Which of the following is the most likely reason a patient may not obtain relief from oxycodone? The patient possesses…
a. an extra copy of the CYP 2D6 gene
b. the CYP 2C91 allele
c. the CYP 2D62 allele
d. the CYP 2D6*3 allele
d. the CYP 2D6*3 allele– codeine is a CYP 2D6 substrate; 1,2, *35 are the only alleles coded for extensive metabolizers
Which of the following dietary supplements is most likely to interact with metoprolol causing extensive hypotension?
a. goldenseal
b. St. John’s wort
c. ginseng
d. echimacea
a. goldenseal
St. John’s wort has a profound effect on the plasma levels of many co-administered medications since it has a double effect on CYP 3A4 and P-gp. This effect is:
a. inhibition
b. induction
c. deduction
d. reduction
b. induction
A P-gp inhibitor is likely to result in:
a. drug that is a P-gp substrate being expelled from cells
b. increased flow of P-gp substrate into an enterocyte
c. hepatic enzyme inhibition
d. no effect on P-gp substrates that are also drugs
b. increased flow of P-gp substrate into an
Suicide (mechanism based) inhibitors cause long-acting effects because:
a. the CYP enzyme is destroyed
b. the drug forms a covalent bond and this is destroyed
c. the metabolite of the drug forms a covalent bond and this is destroyed
d. they represent a form of competitive inhibition
a. the CYP enzyme is destroyed
Which of the following is likely to induce metabolism of dextromethorphan?
a. rifampin
b. St. John’s wort
c. phenytoin
d. none of the above
d. none of the above– no known inducers of CYP 2D6
With regard to SNP’s, which of the following is not true?
a. heterozygous non synonymous SNPs can produce a diminished extensive metabolizer phenotype
b. homozygous non synonymous SNPs can produce a poor metabolizer phenotype
c. homozygous synonymous SNPs can produce a poor metabolizer phenotype
d. heterozygous synonymous SNPs can produce an extensive metabolizer phenotype
c. homozygous synonymous SNPs can produce a poor metabolizer phenotype– this codes for the same AA (so no change)
. Sulfonamides are most likely to produce elevated serum levels of which of the following?
a. tolbutamide
b. digoxin
c. pravastatin
d. midazolam
a. tolbutamide
Antihypertensive medications should not be used with dietary supplements containing which of the following botanicals?
a. guarana
b. echinacea
c. saw palmetto
d. ginkgo biloba
e. ginseng
a. guarana
Genotyping can significantly reduce the incidence of severe toxicity for which of the following cancer chemotherapeutic agent?
a. doxorubicin
b. paclitaxel
c. azathioprine
d. irinotecan
e. A & B
f. C & D
f. C & D
- Which of the following issues can contribute to the incidence of herb-drug interactions?
a. variability in product content and potency
b. lack of notification of supplementation usage to health care providers
c. lack of safety and efficacy studies prior to marketing
d. adulteration with conventional medications
e. all of the above
f. none of the above
e. all of the above
Which of the following statements is true regarding the interaction between penicillin and probenecid?
a. probenecid induces the renal uptake transporter OAT
b. probenecid inhibits the renal uptake transporter OAT
c. probenecid decreases the half life of penicillin
d. probenecid increases the renal clearance of penicillin
e. probenecid inhibits CYP 3A4
b. probenecid inhibits the renal uptake transporter OAT
Transplant recipients immunosuppressed with cyclosporine are at possible risk for nephrotoxicity when ingesting which herbal supplement?
a. ginseng
b. goldenseal
c. echinacea
d. St. John’s wort
e. ginkgo biloba
d. St. John’s wort
Which of the following nuclear receptors is responsible for up regulating transcription of the CYP 2D6 gene?
a. steroid xenobiotic receptor
b. constitutive androstane receptor
c. vitamin D3 receptor
d. aryl hydrocarbon receptor
e. all of the above
f. none of the above
f. none of the above
Clarithromycin can produce elevated digoxin concentrations by which of the following mechanisms?
a. inhibition of CYP 1A2
b. inhibition of CYP 3A4
c. inhibition of CYP 2C9
d. inhibition of OATP
e. inhibition of ABCB1
e. inhibition of ABCB1
High quality St. John’s wort induces the metabolism of which of the following CYP 2D6 substrates?
a. nortriptyline
b. desimpramine
c. fluoxetine
d. all of the above
e. none of the above
e. none of the above– no known inducers of CYP 2D6
