Chapter 4 - Xenobiotic Transformation Flashcards
All of the following are true of CYP2D6 except…
A. It converts codine to morphine
B. It is polymorphic
C. It is induced by quinidine
D. Poor metabolizers have a lower risk of lung cancer
C. It is induced by quinidine
A probe drug for human CYP2C19 is…
A. Mephenytoin
B. Valproic acid
C. Carbamazepine
D. Warfarin
A. Mephenytoin
Aryl hydrocarbon receptor agonists include all of the following except…
A. TCDD
B. Benzopyrene
C. 3-methylcholanthrene
D. Benzene
D. Benzene
Enzyme induction in humans has been asso w/…
A. Osteomalacia
B. Hepatocellular carcinoma
C. Cirrhosis
D. Psoriasis
D. Psoriasis
In metabolism-dependent inhibition of cytochrome P450…
A. The parent compound is a potent inhibitor
B. The metabolite must be a product of P450 catalysis
C. The metabolite is a potent inhibitor
D. The inhibition is always irreversible
C. The metabolite is a potent inhibitor
A compound that induces CYP2D6 is…
A. Rifampin
B. Dexamethazone
C. Ethanol
D. None of the above
D. None of the above
All of the following are considered phase I biotransformation reactions except…
A. Hydrolysis
B. Conjugation
C. Reduction
D. Oxidation
B. Conjugation
All of the following statements are true except…
A. Forms of epoxide hydrolase can exist in both microsomes and cytosol
B. Gemfibrozil is conjugated with glucuronic acid before it is oxidized by cytochrome P450
C. CYP2D6 and CYP2D9 metabolize over half the drugs in current use
D. Biotransformation can take place in the gut
C. CYP2D6 and CYP2D9 metabolize over half the drugs in current use
UDP glucuronyltransferases conjugate all of the following endogenous molecules except…
A. Thyroid hormone
B. Bilirubin
C. Steroid hormones
D. Parathyroid hormone
D. Parathyroid hormone
If codine were given to a patient who was 2D6 ultrametabolizer, the most likely result would be…
A. Inadequate analgesia
B. Higher than normal levels of morphine at 2 hrs postdose
C. Higher than normal levels of codine at 4 hrs postdose
D. Higher than normal levels of oxycodone at 4 hrs postdose
B. Higher than normal levels of morphine at 2 hrs postdose
A victim drug is…
A. A drug whose clearance is determined mostly by a single route of elimination
B. A drug that induces neutralizing antibodies
C. A drug that is unstable in plasma
D. A racemic drug mixture where one isomer inhibits the metabolism of the other isomer
A. A drug whose clearance is determined mostly by a single route of elimination
Terfenadine and ketoconazole are examples of…
A. Enzyme inducers
B. Perpetrator and inhibitor
C. Victim drug and perpetrator
D. Drugs with limited biotransformation
C. Victim drug and perpetrator
All of the following are true except…
A. Hyperforin induces CYP3A4
B. Broccoli inhibits 1A2
C. Grapefruit juice inhibits intestinal CYP3A4
D. Drugs that inhibit transporters can help anticancer agents
B. Broccoli inhibits 1A2
Levels of UDPGA and PAPS are lowered by…
A. Saint John’s wort
B. Phenobarbital
C. Rifampin
D. Fasting
D. Fasting
An example of a pair of enantiomers in which one inhibits CYP2D6 and the other has little activity is…
A. R and S methadone
B. R and S warfarin
C. R and S mephenytoin
D. Quinidine and quinine
D. Quinidine and quinine
Which of the following biotransformation enzyme-subcellular location pairs is correct…
A. Alkaline phosphatase-cell membrane
B. Carboxyesterase-blood
C. Sulfotransferase-cytosol
D. All of the above
D. All of the above
The least likely biotransformation reaction that aniline would undergo is…
A. Halogenation
B. Aromatic hydroxylation
C. N-acetylation
D. N-glucuronidation
A. Halogenation
The proteins KEAP1 and Nrf2…
A. Suppress CYP expression in response to inflammation
B. induce enzymes in response to oxidative stress
C. Promotes DNA methylation
D. None of the above
B. induce enzymes in response to oxidative stress
All of the following are true of glutathione except…
A. Germ cells and ovum have high levels
B. Conjugation of dibromoethane results in a mutagenic metabolite
C. Conjugation of electrophiles is a major means of protecting DNA
D. Conjugation always occurs enzymatically
D. Conjugation always occurs enzymatically
Phenobarbital…
A. Causes liver tumors in humans and rodents
B. Causes liver tumors in rodents but not humans
C. Causes liver tumors in primates but not rodents
D. Causes liver tumors in rodents and nasal tumors in humans
B. Causes liver tumors in rodents but not humans
All of the following are hydrolytic enzymes except…
A. Carboxyesterase
B. Alcohol dehydrogenase
C. Cholinesterase
D. Paraoxonase
B. Alcohol dehydrogenase
All of the following are true of epoxide hydrolases except…
A. They add oxygen to a double bond and form a 3- member ring
B. They are important in detoxifying electrophiles
C. They play a role in converting benzo(a)pyrene to a carcinogen
D. Some forms are inducible
A. They add oxygen to a double bond and form a 3- member ring
Nitroreductase plays an important role in…
A. Nasal epithelium
B. Lung Clara cells
C. White blood cells
D. Intestinal microflora
D. Intestinal microflora
A drug that undergoes sulfoxide reduction is…
A. Haloperidol
B. chloramphenicol
C. Thalidomide
D. Sulindac
D. Sulindac
Under low oxygen tensions, reduction reactions can be catalyzed by…
A. Cytochrome P450
B. NADPH quinine oxioreductase
C. Cytosolic aldehyde oxidase
D. All of the above
D. All of the above
Quinine oxioreductases are thought to play a protective role in…
A. Liver toxicity of microcystin
B. Bone marrow toxicity of benzene
C. Renal toxicity of aminoglycosides
D. Neurotoxicity of n-hexane
B. Bone marrow toxicity of benzene
All of the following are mechanisms for removing halogen atoms from aliphatic xenobiotics except…
A. Grignard dehalogenation
B. Reductive dehalogenation
C. Oxidative dehalogenation
D. Double dehalogenation
A. Grignard dehalogenation
Oxidation of ethanol to acetaldehyde takes place in…
A. Cytosol
B. Microsomes
C. Peroxisomes
D. All of the above
D. All of the above
Reductive dehalogenation of carbon tetrachloride produces…
A. Phosgene
B. chloroform
C. Trichloromethyl radical
D. Hydrochloric acid
C. Trichloromethyl radical
Acetaldehyde is converted to acetic acid by ALDH2 in…
A. Mitochondria
B. cytosol
C. Microsomes
D. All of the above
A. Mitochondria
Aldehyde oxidase and xanthene oxioreductase contain…
A. Zinc
B. Molybdenum
C. Selenium
D. Copper
B. Molybdenum
The major metabolite of nicotine excreted into the urine is..
A. Nicotinamide
B. Nicotine glucuronide
C. Cotinine
D. Niacin
C. Cotinine
All of the following are true of myloperoxidase (MPO) except…
A. It is present in neutrophils
B. It can be induced by cyanide ion
C. It forms reactive metabolites of drugs that cause agranulocytones
D. It is polymorphic
B. It can be induced by cyanide ion
Patients with Parkinson’s disease have elevated levels of which of the following enzymes in the substantia nigra region of the brain…
A. COMT
B. Aldehyde oxidase
C. CYP2E1
D. MAO-B
D. MAO-B
All of the following are true of prostaglandin H synthase (PHS) enzymes except..
A. They are known a COX1 and COX 2
B. They convert xenobiotics to carcinogenic metabolites
C. They can be inhibited by drugs
D. They mainly cause toxicity in tissues that contain a high concentration of cytochrome P450
D. They mainly cause toxicity in tissues that contain a high concentration of cytochrome P450
The reactions catalyzed by flavin monooxygenases are most similar to those catalyzed by…
A. MAO-A
B. Cytochrome P450
C. UDP-glucuronyltransferase
D. Xanthine oxidase
B. Cytochrome P450