Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Pharmacokinetics > Flashcards

Pharmacokinetics Flashcards

1
Q

Study of the mechanisms and quantitative characteristics of drug liberation, drug absorption, distribution, metabolism/biotransformation, and excretion (ADME)

A

Pharmacokinetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

4 aspects studied by pharmacokinetics

A

Drug absorption, distribution, metabolism/biotransformation, and excretion (ADME)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

passage of drug between site of administration and vascular compartment

A

Absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Enteral routes of administration (4)

A

Oral, buccal, sublingual, rectal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

3 Non-alimentary routes of administration

A

Pulmonary/inhalation, Parenteral (IV, intraperitoneal, intra-arterial, intraspinal, subcutaneous, intramuscular), topical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Many quick dissolve drugs are not actually sublingual or buccal forms, but simply this

A

Drug delivery systems that quickly dissolve in the moisture of the mouth
Dissolved drug must be swallowed for absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Sublingual and buccal routes of administration are limited to drugs that are _____ soluble and taste good

A

Lipid soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

4 factors that affect GI function and can affect oral drug absorption

A

Drug characteristics
Transit time
Absorptive surface area
Food may interfere with dissolution and absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Can you split extended release tablets/capsules/pills?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Route of administration that is Usable in unconscious patient, vomiting patient, and in infants
Compliance is major problem
Good absorptive profile
NO first pass effect

A

Rectal route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is there first pass effect with rectal route of administration?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

To be absorbed in the stomach, a drug must be ______

A

Acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Basic drugs likely get absorbed here

A

In the intestine
If they survive the acidic environment of the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Occurs when portal blood delivers a drug to the liver
The liver biotransforms the drug before it reaches systemic circulation
OR Liver extracts the drug into the bile before it reaches systemic circulation
Net effect: the amount of unchanged drug entering systemic circulation is reduced
May represent a loss of bioavailability

A

First Pass Effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the net effect of the First Pass Effect

A

The amount of unchanged drug entering systemic circulation is reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The first pass effect occurs because of this

A

Portal blood delivers drug to liver where it is biotransformed or extracted into the bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Oral nitroglycerin is subject to this

A

First pass effect
Use sublingual route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Oral drug that is subject to first pass effect and uses sublingual route

A

Nitroglycerin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Primary area of absorption for oral route

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Organ with large absorptive surface area
Possible first pass effect

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Does the first pass effect occur with the small intestine?

A

Possible yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Most absorption in the small intestine occurs here

A

In first 2 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Small intestine is primary area of absorption for this route

A

Oral route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Organ with limited role in drug absorption; small absorptive surface area, long ‘contact’ time
Dense contents limits access to absorptive surface

A

Large intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The inhalation route has good absorptive capacity here

A

In alveolar spaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Route that is closest to ideal for diffusion
High surface area; highly permeable membranes
Many drugs do not reach this space, are not absorbed; Requires gas, aerosol or fine particle

A

Inhalation route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

3 common adverse effects of the inhalation route

A

Cough, irritation of throat, bronchospasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What type of drugs are inhalers for asthma and COPD?

A

Topical drugs (not inhaled drugs)
Only deliver drug to the upper airway structures without necessary entry into blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Route of administration where systemic absorption is normally minimal
Drug must be non-irritating
Compliance depends on physical characteristics of drug or vehicle

A

Topical route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Systemic absorption with the topical route is increased with these 4 factors

A

Increased lipid solubility
Conditions associated with enhanced skin permeability
Application to large surface area
High dosages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Route of administration that uses patch medications
Highly lipophilic drugs only
Generally used for short acting drugs
Slow onset of effect may be a limiting feature

A

Transdermal delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Transdermal deliver requires this type of drugs only

A

Highly lipophilic drugs only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Patch medications use this type of delivery

A

Transdermal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Route of administration involving proteins absorbed via lymph
Vehicle, volume, surface area, site of administration, environmental factors all contribute to absorption
Implants or suspensions can be used

A

Subcutaneous or intramuscular routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Drugs given via the subcutaneous or intramuscular routes are absorbed via this

A

Lymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Route of administration where sterile techniques and materials are obligatory
Rate of administration is important variable
Irreversible as drug is automatically in blood (so not real absorption)
Drug must be water soluble or micro-suspension
Only routes guaranteed to provide 100% bioavailability

A

Intravenous or intra-arterial routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Only routes of administration guaranteed to provide 100% bioavailability

A

Intravenous or intra-arterial routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Routes of administration where there is no absorption since drug is directly applied to the vascular space

A

Intravenous or intra-arterial routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Routes of administration that are irreversible as drug is automatically in blood

A

Intravenous or intra-arterial routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Intravenous or intra-arterial routes requires drugs that are this

A

Water soluble or micro-suspension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Does the first pass effect occur with the intraperitoneal route?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Route that is similar to oral without the problems associated with the stomach or intestine
First pass effect

A

Intraperitoneal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Route of administration where Drug is placed inside meninges
Requires high degree of training and skill
Little margin for error permitted
Ensues access to CNS with all inherent risks
NOT the same as an epidural

A

Intrathecal route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Drugs given via the intrathecal route are placed here

A

Inside meninges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

4 drug characteristics that favor crossing membranes

A

Uncharged
Nonpolar
Low molecular weight
High lipid solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Drug permeation process that is not saturable; most drugs use this to move along concentration gradient
Paracellular transport
Diffusion is most important limiting factor

A

Passive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Drug permeation process that is saturable, can be facilitated or active transport (moves substance against gradient)

A

Special carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Drug permeation process that used for proteins and very large molecules

A

Endocytosis/exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Number used to predict the membrane permeability of a drug at different pH values

A

Negative log of a drug’s dissociation constant (pKa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Henderson-Hasselbalch can be used to predict this

A

How much drug crosses membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Used to predict the portion of a drug that will permeate a membrane in a given pH environment based on the drug pKa

A

Henderson-Hasselbalch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Degree of ionization for weak acids are greater at ______ pH

A

Higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Degree of ionization for weak acids are lesser at ______ pH

A

Lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Degree of ionization for weak bases are greater at ______ pH

A

Lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Degree of ionization for weak bases are lesser at ______ pH

A

Higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Is the pKa for a drug constant?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Will a weak acid be ionized when solvent pH is less than its pKa?

A

Unionized
(acid - acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Will a weak acid be ionized when solvent pH is more than its pKa?

A

Ionized
(base - acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Will a weak base be ionized when solvent pH is less than its pKa?

A

Ionized
(acid - base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Will a weak base be ionized when solvent pH is more than its pKa?

A

Unionized
(base - base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

If pH < pKa, solvent is _____ relative to drug

A

Acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

If pH > pKa, solvent is _____ relative to drug

A

Basic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Weak acids are ionized in ______ solvents

A

Basic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Weak acids are unionized in ______ solvents

A

Acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Weak bases are ionized in ______ solvents

A

Acidic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Weak bases are unionized in ______ solvents

A

Basic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

10 ^ ([pH - pKa]) predicts this

A

Ratio of drug ionized to unionized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

ATP-driven efflux transporter expressed in intestine and other tissues
‘Pumps’ drugs back into the intestinal lumen or out of cells and into blood
Substrates include anti-cancer drugs, immunosuppressive drugs and some drugs used to treat heart failure
Reduces absorption

A

P-glycoprotein (Pgp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

P-glycoprotein does this

A

Pumps drugs back into intestinal lumen or out of cells and into blood
Reduces absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

P-glycoprotein expression is increased by this

A

TB antibiotic rifampicin
Leads to reduced drug absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

TB antibiotic rifampicin has this affect on P-glycoprotein

A

Induces expression, leads to reduced drug absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

TB antibiotic rifampicin has this affect on drug absorption

A

Reduces due to increased expression of P-glycoprotein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

P-glycoprotein is inhibited by this drug, thus increasing drug absorption

A

Verapamil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Fraction of total drug administered that is transferred to blood (how much drug eventually gets into circulation)

A

Bioavailability (F)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Bioavailability (F) of IV route

A

100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Oral route has bioavailability F<100% due to this

A

First pass metabolism by liver and incomplete absorption into systemic blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Effect that removes drug before systemic circulation

A

First pass metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

This can be reduced by formation of insoluble complexes in GI

A

Bioavailability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Equation to convert dosage when changing drug formulation

A

Dose1 x F1 = Dose2 x F2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

How many nanograms in a microgram?

A

1 ug = 1000 ng

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Blood flow to a tissue/region determines the rate of drug delivery and can contribute to termination of drug action

A

Distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Key concept of distribution
A mathematically definable space to which drug may enter and exit

A

Compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

3 possible compartments involved in drug distribution

A

Plasma, interstitial fluid, and cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Changes in this compartment will be directly reflective of changes in connected areas

A

Plasma

85
Q

Describe the one compartment model of distribution

A

Plasma is in equilibrium with interstitial areas and is accessible
Changes in plasma will be directly reflective of changes in connected areas
Plasma is surrogate for other compartments

86
Q

Equation for volume; used to understand drug distribution throughout a compartment

A

Volume = Dose / Plasma Concentration

87
Q

hypothetical volume in which a dose (D) of drug would have to be placed in to obtain the measured plasma concentration (Cp)

A

Volume of distribution (Vd)
Vd = D / Plasma concentration = (mg/kg) / (mg/L) = L/kg

88
Q

Vd of 3-5 indicates a drug is likely distributed in this

A

Plasma water

89
Q

Vd of 5-10 indicates a drug is likely distributed in this

A

Blood volume

90
Q

Vd of 10-20 indicates a drug is likely distributed in this

A

Interstitial space

91
Q

Vd of 22-42 indicates a drug is likely distributed in this

A

Total body water

92
Q

Vd of >70 indicates a drug is likely distributed in this

A

Tissue bound (or even accumulating)

93
Q

Vd is inversely related to this

A

Drug concentration for a given dose

94
Q

Large Vd are associated with low drug plasma concentration and imply high ______ solubility

A

High lipid solubility (low water solubility)

95
Q

Small Vd are associated with high drug plasma concentration and imply high ______ solubility

A

High water solubility (low lipid solubility)

96
Q

Does large or small Vd have longer durations of action?

A

Large

97
Q

Does large or small Vd have shorter durations of action?

A

Small

98
Q

Does large Vd indicate long or short durations of action?

A

Long

99
Q

Does small Vd indicate long or short durations of action?

A

Short

100
Q

Describes how much drug must be given at one time to achieve effective blood levels
Used to achieve a desired blood level (concentration at steady state) quickly and reliably

A

Loading dose = Vd x TC/F
TC = target concentration

101
Q

Equation for loading dose

A

Loading dose = Vd x TC/F
(TC = target concentation; F = bioavailability)

102
Q

What is loading dose used for?

A

Used to achieve a desired blood level (concentration at steady state) quickly and reliably

103
Q

Only _____ drug is active drug

A

Free drug

104
Q

Protein binding typically parallels increased _______

A

Lipid solubility

105
Q

This typically parallels increased lipid solubility

A

Protein binding

106
Q

Are drugs with large or small Vd often highly protein bound?

A

Large

107
Q

Most common acceptor protein in the body; 50% serum protein

A

Albumin

108
Q

Common acceptor protein binding cardiovascular and centrally acting drugs

A

Alpha1-acid glycoprotein

109
Q

3 drug acceptor proteins

A

Albumin
Lipoprotein
Alpha1-acid glycoprotein

110
Q

Process of enzymatic biotransformation of a drug into another compound (a metabolite)
Generally regarded as a function of the liver, though GI tract, kidney and placenta have capacity
Usually results in drug conversion to a more polar form more likely to be renally excreted
Not always an inactivation process, as the metabolite may be the active form of the drug.

A

Metabolism/biotransformation

111
Q

Metabolism usually results in drug conversion to a more ______ form that is more likely to be renally excreted

A

Polar

112
Q

Type of drugs that have little or no activity until biotransformed

A

Prodrugs

113
Q

Two primary biotransformation pathways

A

Phase I reactions (oxidation, reduction, hydrolysis)
Phase II reactions (conjugation, acetylation, methylation)

114
Q

3 types of reactions involved in phase I reactions of biotransformation

A

Oxidation, reduction, hydrolysis

115
Q

3 types of reactions involved in phase II reactions of biotransformation

A

Conjugation, acetylation, methylation

116
Q

Most common phase I reaction

A

Oxidation

117
Q

Most important oxidation system of phase I reactions of biotransformation

A

Cytochrome P450 oxidative system (CYP, mixed function oxidase (MFO), monooxygenase, microsomal enzyme system)

118
Q

Phase I or II reactions of biotransformation:
Destructive pathways as primary compound is forever changed
Often diminished in elderly patients

A

Phase I

119
Q

Cytochrome P450 oxidative system is involved in Phase I or II reactions of biotransformation?

A

Phase I

120
Q

Are these reactions Phase I or II of biotransformation:
Oxidation, reduction, hydrolysis

A

Phase I

121
Q

Are these reactions Phase I or II of biotransformation:
Conjugation, acetylation, methylation

A

Phase II

122
Q

Intracellular location of cytochrome P450 oxidative system

A

Endoplasmic reticulum

123
Q

Predominant CYP isoform; amount and importance, accounts for a lot of first pass effect
High interaction potential
Few genetic polymorphisms

A

CYP 3A4/5

124
Q

CYP 3A4/5 is induced by

A

Smoke and some vegetables

125
Q

CYP 3A4/5 is inhibited by

A

Some antibiotics (quinolone and macrolides) and grapefruit

126
Q

Partial irreversible inhibitor of CYP 3A4

A

Grapefruit

127
Q

CYP 3A4/5 is especially important for these drugs

A

Orally administered drugs biotransformed by intestinal wall CYP3A4 enzymes
E.g. lovastatin (Mevacor)

128
Q

Recovery half-life of CYP 3A4/5

A

About one day

129
Q

Does CYP 3A4/5 have genetic polymorphisms?

A

No; few

130
Q

Grapefruit is a partial irreversible inhibitor of this

A

CYP 3A4

131
Q

CYP that is especially important for orally administered drugs biotransformed by intestinal wall
E.g. lovastain (Mevacor)

A

CYP 3A4

132
Q

CYP with high interaction potential
Induced by many drugs (anticonvulsants, warfarin)
Clinically important genetic polymorphisms have different metabolizing capacity than more common genotypes (some are poor metabolizers, reducing first pass metabolism and patient exposure to drugs)

A

CYP 2C8/9/10

133
Q

Drugs that induce CYP 2C8/9/10

A

Anticonvulsants and warfarin

134
Q

Does CYP 2C8/9/10 have genetic polymorphisms?

A

Yes!
Clinically important genetic polymorphisms in CYP2C9 and CYP2C19 have different metabolizing capacity than more common genotypes
Some are poor metabolizers, reducing first pass metabolism and patient exposure to drugs

135
Q

Does CYP 3A4/5 have high or low interaction potential?

A

High

136
Q

Does CYP 2C8/9/10 have high or low interaction potential?

A

High

137
Q

Second most predominant CYP isoform
Highest number of genetic polymorphisms
Deficiencies are common; hyper metabolizers are noted
Several inhibitors noted including many cardiovascular and psychoactive drugs

A

CYP 2D6

138
Q

Does CYP 2D6 have genetic polymorphisms?

A

Yes! Highest number of genetic polymorphisms
7% Caucasians are deficient
1-3% African Americans and Asians are deficient
Hyper metabolizers (multiple copies of CYP 2D6 gene) are noted

139
Q

Percentage of caucasians that are deficient in CYP 2D6

A

7%

140
Q

Percentage of African Americans and Asians are deficient in CYP 2D6

A

1-3%

141
Q

30% of cytochrome P450 interactions involve this CYP

A

CYP 2D6

142
Q

Hyper metabolizers (multiple copies of the CYP gene) are noted for this CYP

A

CYP 2D6

143
Q

Inhibitors of CYP 2D6

A

Cardiovascular and pyschoactive drugs

144
Q

Drugs that inhibit CYP450 activity are often this mechanism-based

A

Covalent “suicide” inhibitors

145
Q

5 drugs that induce CYP expression

A

Anticonvulsants
Rifampin (anti TB)
Chronic alcohol
Glucocorticoids
Phenobarbital

146
Q

Induction of CYP involves increased this

A

Heme protein synthesis

147
Q

Induction of an increase in CYP450 expression results from this

A

Elevated CYP450 mRNA production

148
Q

Deficiency of heme synthesis pathways and during CYP induction toxic levels of heme proteins may accumulate

A

Porphyria

149
Q

Porphyria is this

A

Deficiency of heme synthesis pathways
During CYP induction toxic levels of heme proteins may accumulate

150
Q

Phase I or II reactions of biotransformation:
Synthetic pathways as primary compound is chemically added; attaches a polar group to the drug by transferase enzymes
Final result generally very polar compared to parent compound, more likely to make product excretable (renally or in bile) than phase 1 process

A

Phase II

151
Q

Final result of phase II reactions is generally ________ compared to parent compound, and more likely to be excreted (renal or bile) than phase I process

A

Very polar

152
Q

Kidneys can’t easily eliminate _________ drugs, so these drugs need to be made more hydrophilic by phase I and II reactions

A

Lipophilic (membrane permeable)

153
Q

Is conjugated drug usually active or inactive?

A

Inactive

154
Q

Following Phase I reactions, drug is most often _______

A

Inactivated

155
Q

6 factors that affect drug biotransformation

A

Enzyme induction
Genetics
Age
Nutrition
Disease (hepatitis, cirrhosis)
Other drugs

156
Q

Does increased activity or cytochrome P450 system enhance or reduce metabolism of substrates?

A

Enhance
Drugs removed faster, inadequate dose, subtherapeutic levels

157
Q

Levels of drug biotransformation in newborn

A

Limited

158
Q

Levels of drug biotransformation in adolescence

A

Unstable and often high

159
Q

Levels of drug biotransformation in puberty

A

Relatively high

160
Q

Levels of drug biotransformation in great age

A

Diminished

161
Q

Nutrition reduces biotransformation in these 3 conditions

A

Protein deficiency
Diets deficient in essential fatty acids
Excessive intake of glucose, sucrose, or fructose

162
Q

2 diseases that affect drug biotransformation

A

Hepatitis, cirrhosis

163
Q

Two primary mechanisms for clearing drugs and their metabolites from the body:

A

Hepatic and biliary clearance
Renal clearance

164
Q

Renal drug clearance mechanisms are the same as for endogenous substances and include these 3 mechanisms:

A

Glomerular filtration
Tubular secretion (active process)
Tubular reabsorption (may be active or passive, mostly passive diffusion)

165
Q

Is tubular secretion an active or passive process?

A

Active

166
Q

Is tubular reabsorption an active or passive process?

A

May be active or passive
Mostly passive diffusion

167
Q

Only a small fraction of drug is cleared by this in each pass through the kidneys

A

Glomerular filtration

168
Q

Drugs bound to plasma protein are too large to be cleared by this

A

Glomerular filtration

169
Q

Route of elimination that is available to volatiles, diffusion is primary mechanisms
Have relatively high level of biotransformation potential

A

Pulmonary elimination

170
Q

Many drugs are subject to a pulmonary “first pass” effect because of this

A

Lungs have a relatively high level of biotransformation potential

171
Q

Following process such as conjugation with __________, a drug is excreted by the liver cells into the bile and then delivered to the small intestine

A

Glucuronic acid

172
Q

Type of excretion important for some molecules that are anionic, cationic, or non-ionized molecules containing polar or lipophilic groups

A

Biliary excretion

173
Q

When deciding on starting doses for a drug eliminated by renal processes, the patient’s renal function should be assessed by this level

A

Creatinine clearance (CrCl)

174
Q

Normal creatinine clearance (CrCl) range

A

70-160 mg/min

175
Q

Creatinine clearance (CrCl) range that indicates a minor dosage adjustment is needed

A

30-60 mg/min

176
Q

Creatinine clearance (CrCl) range that indicates moderate dosage adjustment is needed

A

15-30 mg/min

177
Q

Creatinine clearance (CrCl) range that indicates a major dosage adjustment is needed

A

Below 15 mg/min

178
Q

_________ has an impact on the magnitude and duration of responses to drugs

A

Pharmacokinetics

179
Q

Equation for clearance

A

Cl = rate of drug elimination / plasma drug concentration

180
Q

Is clearance specific for route of elimination?

A

NO
If multiple routes of elimination exist, the clearance rate is additive

181
Q

Time required for drug serum concentration to decline by one half after absorption and distribution are complete

A

Half life (T 1/2)

182
Q

Do rapidly eliminated drugs (large clearance values) have short or long half lives?

A

Short

183
Q

Do slowly eliminated drugs (small clearance values) have short or long half lives?

A

Long

184
Q

Equation for half life

A

T 1/2 = 0.7 / Ke
(Ke = elimination constant for that drug)

185
Q

Relation between clearance and half life

A

Clearance is inversely related to half life

186
Q

Two primary mathematical models of elimination

A

Zero (aka linear) and first (aka nonlinear) order kinetics

187
Q

Mathematical modeling of elimination:
Amount per unit time
Rate is constant and independent of drug
Typical of biological processes that are saturated
Unusual
Dependent on starting drug concentration
Half-life is not constant, but each subsequent half-life is half of the preceding one

A

Zero order kinetics (aka linear or saturation kinetics)

188
Q

Mathematical modeling of elimination:
Fractions per unit time
Rate is diminishing and always in proportion to the amount of drug in the body
Typical
Half-life is constant regardless of drug concentration

A

First order kinetics (aka nonlinear kinetics)

189
Q

Mathematical modeling of elimination:
Amount per unit time

A

Zero order kinetics

190
Q

Mathematical modeling of elimination:
Fractions per unit time

A

First order kinetics

191
Q

First order kinetics are linearized when using this

A

Semi-log Y-axis

192
Q

Mathematical modeling of elimination:
Half-life is dependent on starting drug concentration

A

Zero order kinetics

193
Q

Mathematical modeling of elimination:
Half-life is constant regardless of drug concentration

A

First order kinetics

194
Q

Zero order kinetics involve _______ per unit time

A

Amount

195
Q

First order kinetics involve _______ per unit time

A

Fractions

196
Q

Mathematical modeling of elimination:
Rate is constant and independent of drug

A

Zero order kinetics

197
Q

Mathematical modeling of elimination:
Rate is diminishing and always in proportion to the amount of drug in the body

A

First order kinetics

198
Q

Pattern of half-life in zero order kinetics

A

Dependent on starting drug concentration
Each subsequent half-life is half of the preceding one

199
Q

Pattern of half-life in first order kinetics

A

Constant regardless of drug concentration

200
Q

Loading and maintenance doses must be corrected for _________ less than 1.0

A

Bioavailabilities (F)

201
Q

Loading and maintenance doses must be corrected for bioavailabilities (F) less than this

A

1.0

202
Q

Once a steady state has been achieved, this can be used to sustain it over time

A

Maintenance dose

203
Q

For maintenance dose, use this as the dosing interval

A

Drug’s half life

204
Q

Maximal blood level is _____ the drug serum concentration achieved with the first dose

A

Twice

205
Q

Minimal blood level is _______ the drug serum concentration achieved with the first dose

A

Equal

206
Q

Loading dose is ______ the maintenance dose

A

Twice

207
Q

Loading dose is twice this

A

Maintenance dose

208
Q

Refers to the condition where overall drug intake is in dynamic equilibrium with its elimination, and is generally achieved within five half-lives (for first order kinetics)

A

Steady state concentration (Css)

209
Q

Equation for steady state concentration (Css)

A

Css = Rate in (infusion rate) / Rate out (elimination/clearance)

Pharmacology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions