PRELIM 02 - Metabolic Changes of Drugs

Question 1

The process by which the drug is chemically converted in the body to a metabolite

Answer 1

Drug metabolism

Question 2

Refers to the formation of inactive and relatively nontoxic compounds

Answer 2

Detoxification

Question 3

Main site of drug metabolism

Answer 3

Liver

Question 4

The first pass effect __________ bioavailability

Answer 4

Decreases

Question 5

Effect wherein drugs are metabolized before they are distributed to the rest of the body

Answer 5

First pass effect

Question 6

Effect that involves the rapid metabolism of an orally administered drug before reaching the general circulation

Answer 6

First pass effect

Question 7

The most important enzyme system affecting drug metabolism

Answer 7

CYP450 enzyme system

Question 8

Cytochrome P450 enzymes are involved in __________

Answer 8

Oxidative biotransformation

Question 9

Cytochrome P450 enzymes are __________

Answer 9

Monooxygenases

Question 10

Caffeine, testosterone, R-warfarin (CYP enzyme)

Answer 10

1A1

Question 11

Acetaminophen, caffeine, phenacetin, R-warfarin (CYP enzyme)

Answer 11

1A2

Question 12

17β-estradiol, testosterone (CYP enzyme)

Answer 12

2A6

Question 13

Cyclophosphamide, erythromycin, testosterone (CYP enzyme)

Answer 13

2B6

Question 14

Acetaminophen, tolbutamide, hexobarbital, S-warfarin, phenytoin, testosterone, R-warfarin, zidovudine (CYP enzyme)

Answer 14

2C-family

Question 15

Acetaminophen, caffeine, chlorzoxazone, halothane (CYP enzyme)

Answer 15

2E1

Question 16

Acetaminophen, codeine, debrisoquine (CYP enzyme)

Answer 16

2D6

Question 17

Acetaminophen, caffeine, carbamazepine, codeine, cortisol, erythromycin, cyclophosphamide, S- and R-warfarin, phenytoin, testosterone, halothane, zidovudine (CYP enzyme)

Answer 17

3A4

Question 18

2 phases of drug metabolism

Answer 18

Phase I, Phase II

Question 19

Phase I is also known as __________

Answer 19

Functionalization reactions

Question 20

Oxidation of aromatic moieties (Phase of drug metabolism)

Answer 20

Phase I (Functionalization reaction)

Question 21

Oxidation of olefins (Phase of drug metabolism)

Answer 21

Phase I (Functionalization reaction)

Question 22

Oxidation of benzylic, allylic carbon atoms, and carbon atoms to carbonyl and imines (Phase of drug metabolism)

Answer 22

Phase I (Functionalization reaction)

Question 23

Oxidation involving carbon-heteroatom systems (Phase of drug metabolism)

Answer 23

Phase I (Functionalization reaction)

Question 24

Oxidation of alcohols and aldehydes (Phase of drug metabolism)

Answer 24

Phase I (Functionalization reaction)

Question 25

Other miscellaneous oxidative reactions (Phase of drug metabolism)

Answer 25

Phase I (Functionalization reaction)

Question 26

Reduction of aldehydes and ketones (Phase of drug metabolism)

Answer 26

Phase I (Functionalization reaction)

Question 27

Reduction of nitro and azo compounds (Phase of drug metabolism)

Answer 27

Phase I (Functionalization reaction)

Question 28

Miscellaneous reductive reactions (Phase of drug metabolism)

Answer 28

Phase I (Functionalization reaction)

Question 29

Hydrolysis of esters and amides (Phase of drug metabolism)

Answer 29

Phase I (Functionalization reaction)

Question 30

Hydration of epoxides and arene oxides by epoxide hydrase (Phase of drug metabolism)

Answer 30

Phase I (Functionalization reaction)

Question 31

Phase II reaction is also known as __________

Answer 31

Conjugation reactions

Question 32

Glucuronic acid conjugation (Phase of drug metabolism)

Answer 32

Phase II (Conjugation reaction)

Question 33

Sulfate conjugation (Phase of drug metabolism)

Answer 33

Phase II (Conjugation reaction)

Question 34

Conjugation with glycine, glutamine, and other amino acids (Phase of drug metabolism)

Answer 34

Phase II (Conjugation reaction)

Question 35

Glutathione or mercapturic acid conjugation (Phase of drug metabolism)

Answer 35

Phase II (Conjugation reaction)

Question 36

Acetylation (Phase of drug metabolism)

Answer 36

Phase II (Conjugation reaction)

Question 37

Methylation (Phase of drug metabolism)

Answer 37

Phase II (Conjugation reaction)

Question 38

Involves the introduction of a functional polar group by direct introduction or modification/unmasking (Phase of drug metabolism)

Answer 38

Phase I (Functionalization reaction)

Question 39

4 functional polar groups (OCNS)

Answer 39

OH, COOH, NH2, SH

Question 40

__________ involves the direct introduction of functional group (Examples of Phase I reactions)

Answer 40

Hydration

Question 41

__________, __________, and __________ involves modifying or unmasking existing functional groups (Examples of Phase I reactions) (ORH)

Answer 41

Oxidation, Reduction, Hydrolysis

Question 42

Involves the conjugation or attachment of small, polar, and ionization endogenous compounds (Phase of drug metabolism)

Answer 42

Phase II (Conjugation reaction)

Question 43

Phase II (Conjugation reactions) are catalyzed by __________

Answer 43

Transferase enzymes

Question 44

Is the most common conjugative pathway in drug metabolism due to readily available supply of D-glucuronic acid (Examples of Phase II reactions)

Answer 44

Glucuronidation

Question 45

In infants and young children, the __________ conjugate is the main urinary product

Answer 45

O-sulfate

Question 46

Involves the conjugation of xenobiotics with sulfate (Examples of Phase II reactions)

Answer 46

Sulfonation/Sulfate conjugation

Question 47

Conjugation of xenobiotics with sulfate occurs primarily with __________

Answer 47

Phenols

Question 48

The sulfate conjugation process involves the activation of inorganic sulfate to the coenzyme __________

Answer 48

3-phosphoadenosine-5-phosphosulfate (PAPS)

Question 49

The amino acids __________ and __________ are used to conjugate carboxylic acids (GG)

Answer 49

Glycine, Glutamine

Question 50

The amino acids glycine and glutamine are used to conjugate __________

Answer 50

Carboxylic acids

Question 51

__________ conjugation is common to most animals

Answer 51

Glycine

Question 52

__________ conjugation appears to be confined mainly to humans and other primates

Answer 52

Glutamine

Question 53

Takes place in most cells; important in detoxifying potentially dangerous environmental toxins (Examples of Phase II reactions)

Answer 53

Glutathione conjugation

Question 54

Xenobiotics conjugated with GSH undergo further biotransformation to give S-substituted N-acetylcysteine products called __________

Answer 54

Mercapturic acids

Question 55

Its main function is to terminate pharmacological activity and detoxification (Examples of Phase II reactions)

Answer 55

Acetylation

Question 56

This variation is genetic and is caused mainly by differences in N-acetyltransferase activity

Answer 56

Acetylation polymorphism

Question 57

__________ and __________ are rapid acetylators (EA)

Answer 57

Eskimos, Asians

Question 58

__________ and some __________ groups are mainly slow acetylators (EW)

Answer 58

Egyptians, Western European

Question 59

Is important in the biosynthesis of many endogenous compounds and in the inactivation of numerous physiologically active biogenic amines (Examples of Phase II reactions)

Answer 59

Methylation

Question 60

The coenzyme involved in methylation reactions is __________

Answer 60

S-Adenosylmethionine (SAM)

Question 61

Women are __________ ethanol metabolizers than men

Answer 61

Slower

Question 62

Biotransformation time of phenylbutazone in rabbits

Answer 62

3 hours

Question 63

Biotransformation time of phenylbutazone in horses

Answer 63

6 hours

Question 64

Biotransformation time of phenylbutazone in monkeys

Answer 64

8 hours

Question 65

Biotransformation time of phenylbutazone in mice

Answer 65

18 hours

Question 66

Biotransformation time of phenylbutazone in man

Answer 66

36 hours

Question 67

Caucasians are __________ acetylators

Answer 67

Slow

Question 68

Meaning of NAPQI (a toxic byproduct of paracetamol metabolism)

Answer 68

N-acetyl-para-benzo-quinone imine

Question 69

Antidote for paracetamol overdose

Answer 69

N-acetylcysteine

Question 70

In __________, phase II reaction occurs first before phase I

Answer 70

Paracetamol

Question 71

Reduction of a nitro group yields an __________

Answer 71

Amine

Question 72

Reduction of a disulfide group yields a __________

Answer 72

Thiol

Question 73

Oxidation of an amine group yields a __________

Answer 73

Nitro

Question 74

Oxidation of a thiol group yields a __________

Answer 74

Disulfide

Question 75

Digestion of carbohydrates starts in the __________

Answer 75

Mouth

Question 76

Digestion of proteins starts in the __________

Answer 76

Stomach

Question 77

Phase I is more likely to cross the __________ than Phase II

Answer 77

Cell membrane

Question 78

Glucuronidation involves the attachment of glucuronic acid to functional groups like __________, __________, and __________ (PAC)

Answer 78

Phenol, Alcohol, Carboxylic acid

Question 79

The most hepatotoxic anti-TB drug

Answer 79

Isoniazid

Question 80

N-acetylcysteine is given instead of glutathione during a paracetamol overdose because of __________

Answer 80

Le Chatelier's principle

Question 81

2 rate limiting steps of drug metabolism (SP)

Answer 81

Solubility (↑↓↑↓), Permeability (↑↑↓↓)

Question 82

Approximately __________ to __________% of Caucasians lack CYP2D6 activity

Answer 82

5-14%

Question 83

Approximately __________ to __________% of Africans lack CYP2D6 activity

Answer 83

0-5%

Question 84

Approximately __________ to __________% of Asians lack CYP2D56 activity

Answer 84

0-1%

Question 85

Enzyme responsible for converting methanol to acetaldehyde

Answer 85

Alcohol dehydrogenase

Question 86

Enzyme responsible for converting ethylamine to acetaldehyde

Answer 86

Monoamine oxidase (MAO)