M1: Ch3 Drug Absorption & Distribution Flashcards

0
Q

Refers to Drug Fate

A

Metabolism & Excretion

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1
Q

Refers to Drug Disposition

A

Absorption & Distribution

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2
Q

Delivery of drug to the tissue

A

Distribution

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3
Q

Passage of drug from its site of administration into the blood

A

Absorption

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4
Q

Most important transfer mechanism for foreign substance. Down a concentration gradient. Drug molecules pass from high to low concentration.

A

Passive Diffusion

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5
Q

Pass to different pores of membrane via fenestrations. Important for small molecules.

A

Filtration

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6
Q

Example of an organ that utilizes Filtration

A

Kindney (Glomeruli)

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7
Q

Agains a concentration gradient. Energy-dependent, Selective carrier-mediated & Saturable. From Low to High concentration. Uphill and against a concentration gradient.

A

Active transport

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8
Q

Drugs that uses Active transport

A

Levodopa, Iron, PTU & 5-FU “LIP 5”

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9
Q

Drugs that uses Active transport: for thyroid problems

A

PTU

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10
Q

Drugs that uses Active transport: for parkinsonism

A

Levodopa

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11
Q

Drugs that uses Active transport: for cancer

A

5-FU

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12
Q

Drugs that uses Active transport: for blood dyscrasia

A

Iron

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13
Q

Down a concentration gradient. Does not require energy. Selective carrier-mediated. Saturable. Never against a concentration gradient. High to Low concentration.

A

Facilitated Diffusion

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14
Q

Examples of drugs using Facilitated Diffusion

A

Vit. B12/Cobalamin

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15
Q

Complexes with intrinsic factor the goes to ileum them detected by the intestinal cells

A

Vit. B12

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16
Q

Microscopic invaginations capable of cell drinking. In-pouching of cell wall.

A

Pinocytosis

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17
Q

An example of drug that uses Pinocytosis

A

Botulinum toxin

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18
Q

Important in cell absorption. Example is Albumin may not be able to pass thru smaller sized membranes.

A

Basement membrane

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19
Q

Contains tight junctions with tightly packed endothelial junction. Only drugs that have high lipid-water partition coefficient can penetrate.

A

Blood Brain Barrier

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20
Q

BBB uses what mechanism of drug transfer

A

Passive & Facilitated Diffusion

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21
Q

Can increase the permeability of BBB

A

Inflammation (bacterial meningitis & encephalitis)

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22
Q

Substances that are lipid soluble crosses the placenta with relative ease in accordance with their partition coefficient and degree of ionization

A

Placental Barrier

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23
Q

Found at the specialized sertoli-sertoli cell junction, prevents certain chemotherapeutic agents thus hinders treatment of neoplasm.

A

Blood-Testis Barrier

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24
Q

Four Parameters that Influence the rate of diffusion of drugs

A

Thickness, Permeability Coefficient, Surface Area & Concentration Gradient “TPS C”

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25
Q

Fick’s Law of Diffusion: Increase Concentration Gradient = _________ Diffusion.

A

Decrease

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26
Q

Fick’s Law of Diffusion: Increase of Surface Area = ________ Diffusion.

A

Increase

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27
Q

Fick’s Law of Diffusion: Increase of Membrane Thickness = _________ Diffusion.

A

Decrease

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28
Q

Ratio of concentration of a drug in two phases (oil & water) polar & nonpolar. Measure drug affinity to lipid and water.

A

Lipid-Water Partition Coefficient

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29
Q

Formula for Lipid-Water Partition Coefficient

A

Kp = Coil / Cwater

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30
Q

Increase in Kp means

A

Soluble in oil

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31
Q

Decrease Kp means

A

Soluble in water

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32
Q

The polarity of drug influences its

A

Solubility

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33
Q

Increase polarity of drug = _____ water solubility. Thus Kp is ______.

A

Increased. Decreased.

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34
Q

Decrease polarity of drug = _____ water solubility. Thus Kp is ______.

A

Decrease. Increase.

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35
Q

More nonpolar means

A

More soluble to oil

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36
Q

Less nonpolar means

A

Less soluble to oil

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37
Q

Drug that is polar, ionized = ______ Kp (<1); soluble in ________.

A

Decreased. Water.

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38
Q

Drug that is nonpolar, non-ionized = ______ Kp (>1); soluble in ________.

A

Decreased. Lipid.

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39
Q

Ionization extent of Drug is based on

A

pH solution & pKa

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40
Q

Formula for total drug concentration

A

pH - pKa = log R/RH (unprotonated/protonated)

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41
Q

Fully ionized in a region of acidic environment. Goes into Intestine. _______ form will dominate.

A

Weak bases. Unionized.

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42
Q

More lipid soluble substances & able to cross membranes (lipophilic)

A

Unionized form

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43
Q

Base favors basic environment. Intestine is less acidic: ___________.

A

Unionized form

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44
Q

Base favors basic environment. Stomach is acidic: ___________.

A

Ionized form

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45
Q

Causes trapping

A

Ionized form

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46
Q

Able to pass

A

Unionized form

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47
Q

Weak Base in the Intestine is

A

Unionized

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48
Q

Weak Base in the GIT is

A

Ionized

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49
Q

Weak Acid in the GIT is

A

Unionized

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50
Q

Weak Acid in the Intestine is

A

Ionized

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51
Q

2 BE drugs necessarily need to have the same PE?

A

Yes

52
Q

Convenient (easy administration especially capsule and tablet) Requires no medical skills or conditions. Appropriate fro outpatient use and medicines OTC. Those having difficulty in swallowing tablets/capsule can use solution/suspension form.

A

Oral forms

53
Q

Drugs that can’t be taken orally due to GI acidity: sensitive to action of proteases of the gastric enzymes.

A

Insulin

54
Q

Route of administration of Insulin

A

SubQ

55
Q

Drugs that can’t be taken orally due to GI acidity: Antibiotics which are sensitive to gastric acids.

A

Methicillin & Penzylpenicillin

56
Q

Drugs that can’t be taken orally due to GI acidity

A

Oxytocin, Penzylpenicillin, Insulin & Methicillin “OPiM”

57
Q

Oral administered drugs are usually absorbed via

A

Passive Diffusion

58
Q

Solid components separated from liquid. Needs to be shaked.

A

Suspension

59
Q

Fluid preparation

A

Solution

60
Q

Combination of oil & water

A

Emulsion

61
Q

Hard & Chewed in the mouth

A

Lozenges

62
Q

Drugs bypass distribution and undergo metabolism

A

Pre-systemic Metabolism

63
Q

PSM is plotted using

A

Area Concentration Curve (Drug Concentration over Time)

64
Q

An antifungal drug which is inactivated by PSM. Instead uses Isosorbate which is more stable. Also used for angina pectoris.

A

Glyceryl Nitrate

65
Q

An antipsychotic drug that undergoes pre systemic circulation. Huge discrepancy if the drug is given orally versus IM & IV.

A

Chlorpropazine

66
Q

Fractions of the drug which is available in the systemic circulation and obtained by comparing the Area under the curve of drugs with those that of an IV.

A

Bioavailability

67
Q

Formula for Bioavailability

A

BA = AUC oral/ AUC IV x 100

68
Q

Comparing the rate of absorption of two drugs. Rate and Bioavailability after administration are similar with the same route.

A

Bioequivalence

69
Q

Two drugs having the same active ingredient, concentration, form, amount, strength and concentration but doesn’t mean they have the same bioavailability.

A

Pharmaceutic Equivalence

70
Q

Both drugs have the same effect

A

Therapeutic equivalence

71
Q

Renders the drug inactive

A

Presystemic circulation

72
Q

Bioequivalence should always be pharmaceutically equivalent but not all pharmaceutical equivalence is ________.

A

Buoequivalent

73
Q

Inactive drug that becomes active when metabolized.

A

Prodrug

74
Q

Prednesone is a corticosteroid and is inactive. Active form of which is

A

Prednisolone

75
Q

Located in the apical portion of intestinal cells. Principal action is once a molecule gets inside the cell, it will pump out the molecule. Efflux mechanism.

A

P-Glycoprotein

76
Q

GI motility: increase motility (diarrhea) leads to ________ transit time resulting to _______ absorption.

A

Decrease. Decrease.

77
Q

GI motility: decrease motility equals

A

Increase absorption

78
Q

GI motility: increase motility equals

A

Decrease absorption

79
Q

GI motility: Antimuscarinic drug which decreases GI motility

A

Loperamide

80
Q

Passage of blood from the aorta to the different tissues.

A

Splanchnic Blood Flow

81
Q

Decrease Splanchnic Blood Flow (fasting) = _______ rate of drug absorption.

A

Decrease

82
Q

Food & Drugs: increase absorption with intake of a fatty meal

A

Griseofulvin (antifungal)

83
Q

Food & Drugs: increases absorption of drug if taken together.

A

Grapefruit juice + Felodipine (antihypertensive)

84
Q

Food & Drugs: decrease absorption when taken with milk, calcium, FeSo4 and antacids like magnesium because they contain divalent ions.

A

Tetracycline (antibiotic)

85
Q

Other forms of Drug Administration

A

Sublingual, Intravenous/arterial, SubQ, IM, Rectal, Inhalation & Intradermal “SISIRIiN”

86
Q

Angle for IM

A

90°

87
Q

Example of IM drugs

A

Flu vaccine

88
Q

Angle for SubQ

A

45°

89
Q

Example of drugs administered SubQ

A

Insulin

90
Q

Angle for Intradermal

A

10-15°

91
Q

Example for drugs given ID

A

PPD, skin test

92
Q

Examples are Nifedipine & Captopril for gradual decrease of BP

A

Sublingual Administration

93
Q

A denitrate form. A sublingually taken drug.

A

Isodril

94
Q

Examples of drug rectally administered

A

Suppository (Paracetamol)

95
Q

For seizure

A

Diazepam

96
Q

Inhaled but has solid particles

A

Insufflation

97
Q

Drugs that are administered thru Inhalation

A

Salbutamol

98
Q

Drugs absorbed enter the general circulation directly if drug has high lipid-water coefficient. Drug absorption is limited. Extensive network of blood vessels facilitates rapid absorption.

A

Oral cavity & Sublingual Absorption

99
Q

Rich in blood supply and contact with epithelial lining is a potential site for drug absorption. Extent of absorption vary individually.

A

Absorption in the Stomach

100
Q

May affect the degree of ionization thus affecting absorption

A

Low pH

101
Q

Large surface area and high blood perfusion; greater capacity for absorption. Proximal jejunum. Utilizes facilitated, active, filtration and pinocytosis.

A

Absorption from the Small Intestine

102
Q

Smaller absorptive surface area; little absorption. Site of absorption especially for drugs not completely absorbed in the SI.

A

Absorption from the Large Intestine

103
Q

Factors Affecting Rate of GI Absorption

A

Gastric emptying time, Intestinal motility, Food & Formulation factors. “GIFF”

104
Q

Gastric Emptying Time: Increase in GET equals

A

Increase drug absorption

105
Q

Intestinal Motility: Absorption depends on _____ and change in ______.

A

Drug. Motility.

106
Q

Food: Most drug absorption is ______ or ______ in presence of food. Increase __________ increase rate of absorption.

A

Reduced or delayed. Splanchnic blood flow.

107
Q

Ability of drug forms and solubility in highly acidic gastric juice must be considered

A

Formulation factors

108
Q

Major site of administration agents for both local and systemic effects. Facilitated by large surface area of the pulmonary alveolar membrane. Rapid absorption & high lipid-water partition coefficient and smaller molecular radii of such agents.

A

Absorption of drug in the lungs

109
Q

Driving force (measure the capacity of blood to dissolve drug) Absorption of drug in the Lungs.

A

Blood-Air partition coefficient

110
Q

Determined by lipid-water partition coefficient

A

Absorption of drugs through Skin

111
Q

Absorption of drugs through Skin: barrier against rapid penetration of most drugs

A

Stratum corneum (epidermis)

112
Q

Absorption of drugs through Skin: well supplied with blood vessels permeable to both lipid and water soluble compounds.

A

Dermis

113
Q

Most common means of parenteral administration. Increase realibilitu and precision in the drug blood level finally achieved, rapid absorption and onset effect. However, painful, local tissue necrosis and etc.

A

IM & SubQ

114
Q

Ensures immediate pharmacological response. Useful for compounds that are poorly or erratically absorbed. Possible overdose, embolism & infection.

A

IV

115
Q

Factors Influencing Drug Distribution: _________ permeability.

A

Capillary

116
Q

Factors Influencing Drug Distribution: ______________ ratio.

A

Blood flow tissue mass

117
Q

Factors Influencing Drug Distribution: Extent of ________ and specific organ _______.

A

Plasma protein. Binding.

118
Q

Factors Influencing Drug Distribution: Regional differences in _____.

A

pH

119
Q

Factors Influencing Drug Distribution: __________ available.

A

Transport mechanism

120
Q

Factors Influencing Drug Distribution: _________ characteristics of specific tissue membrane.

A

Permeability

121
Q

The volume of fluid required to dissolve the amount of drug in the body. Will move through systems until reach equilibrium.

A

Apparent Volume of Distribution (Vd)

122
Q

Protein Binding: Increase PB = _______ vd, because it is confined in only one area.

A

Decrease

123
Q

Protein Binding: Decrease PB= _______ free drug = ______ vd.

A

Increase. Increase.

124
Q

Dye to measure plasma volume. Binds to albumin. (heparin)

A

Evan’s Blue

125
Q

Water soluble polysaccharide. Does not enter cell. For ECF. (Pen G & Tubocurarine)

A

Inulin

126
Q

To measure Total Body Water. Isotopic labeled water. (Ethanol,digoxin)

A

Deuterium Oxide (D2O)

127
Q

Most are reversible due to hydrophobic characteristic

A

Protein binding

128
Q

Protein binding: the greater the binding, vd becomes ______, _______ available drugs to receptor.

A

Reduced. Lesser.