7: Pharmacology, Pharmacokinetics, Metabolism Flashcards

1
Q

drugs not synthesized within the body

A

xenobiotics

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2
Q

Who said the dose makes the poison?

A

Theophrastus Von Hohenheim (Paracelsus)

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3
Q

actions of the drug on the body; group in which drug belongs

A

pharmacodynamics

*think Drug’s effect on the body = D

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4
Q

actions of the body on the drug (absorption, distribution, metabolism, and elimination ) aka ADME

A

pharmacokinetics

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5
Q

Flux (molecules per unit time) = (c1-c2) x ((area x permeability coefficient))/thickeness

A

Fick’s Law of Diffusion

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6
Q

category of drug absorption expressed as fraction of dose administered; also known as the fraction of unchanged drug reaching circulation

A

Oral Bioavalability (F)

(area under curve)

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7
Q

How are most toxicants absorbed by the body?

A

Simple diffusion

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8
Q

True/False:
Only the unbound drugs (those not bound to proteins) distribute into tissues and receptors, exert pharmacological effects, and are metabolized

A

True

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9
Q

The elimination rate constant; a function of clearance and volume of distribution

A

KEL

Cl = Vd x KEL

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10
Q

A constant relating to drugs rate of transfer/elimination from plasma; units are mL/min

A

Clearance

Cl = kel/Cp

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11
Q

Is clearance used for zero order or first order eliminated drugs?

A

first-order

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12
Q

Type of elimination where processes are saturated (going as fast as they can

-Constant rate of elimination; think of a tub; linear

A

zero-order elimination

i.e. Ethanol

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13
Q

Type of elimination where processes are not saturated; not linear

A

first-order elimination

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14
Q

Time for plasma concentrations to become ½

A

half life, T1/2

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15
Q

Is clearance used for zero order or first order eliminated drugs?

A

first-order

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16
Q

Calculation for half-life

A

T1/2 = 0.693/KEL

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17
Q

hypothetical volume of body fluid (plasma) necessary to contain all of the drug at a concentration equal to the plasma concentration

A

Apparent Volume of Distribution, Vd

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18
Q

Vd of drugs that distribute in total body water (plasma + water)

A

0.7 L/kg male and 0.55 L/kg females (EtOH**)

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19
Q

Route of Administration –>
Put in order of speed of delivery starting w/ fastest:
subcutaneous, IM, IV, Oral

A

(fastest) IV, Intramuscular, subcutaneous, oral (slowest)

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20
Q

when the quantity of drug eliminated in the unit of time equals the quantity of the drug that reaches the systemic circulation in the unit of time.

A

Steady State

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21
Q

How much accumulation/loss is achieved in 1 half life?
4 half lives?
5-6 half lives?

A

1 = 50%
1 = 90%
5-6 = 95-99%

22
Q

What three factors influence clearance?

A

1) dose (timing, was absorption complete)
2) organ blood flow
3) intrinsic function of liver and kidneys

23
Q

range of target plasma concentrations effective for most patients;

A

Therapeutic Range

24
Q

chemical transformation of any xenobiotic

A

Biotransformation

25
Q

Where does biotransformation primarily occur?

A

Liver

26
Q

Step in biotransformation where drugs are converted to more polar metabolite (oxidation, reduction, hydrolysis)

A

Phase I

27
Q

Step in biotransformation where drugs are conjugated w/ larger molecule (endogenous substance) to yield a more easily excreted conjugate; examples: glucuronidation acetylation, sulfation, methylation

A

Phase II

*Most common is glucuronidation

28
Q

Where are drug metabolizing enzymes primarily located?

A

endoplasmic reticulum of liver

29
Q

Common enzymes responsible for biotransformation of drugs

A

Cytochrome p450 familt

CYP 1-3 w/ different isoforms

CYP3A inhibition: grapefruit juice

30
Q

The two most important sits for drug elimination are:

A

Liver and Kidney

31
Q

An antagonist is a type of drug that:
Has maximal efficacy
Has affinity for a receptor but poor efficacy
Binds to a receptor and activates it
Has efficacy but poor affinity
Decreases the concentration of an agonist required to produce
an effect

A

Has affinity for a receptor but poor efficacy

32
Q

An agonist is a type of drug that:
Prevents the metabolism of other drugs
Binds to a receptor without activating it
Simulates the metabolism of other drugs
Competes noncompetitively
Binds to a receptor and activates it

A

Binds to a receptor and activates it

33
Q

True or False: Most drugs are either strong acids or strong bases.

A

False. Most are weakly basic or acidic

34
Q

True or False: In alkaline urine, acidic drugs are more readily ionized.

A

True.

35
Q

True or False: Ionized substances are also referred to as polar substances.

A

True.

36
Q

True or False: The plasma half-life of a drug is directly proportional to total clearance.

A

False.

Think of this equation –> T1/2 = 0.693/KEL

37
Q

True or False: Drugs bound to albumin are inactive

A

True.

38
Q

A classic example of a drug with a high Vd is:
Cocaine
THC
Alprazolam
Ethanol
Isopropanol

A

THC

39
Q

One of the major physiological factors that determines the variability in the rate of drug excretion into the urine is its:
pH
Protein content
Temperature
Volume

A

pH

40
Q

In biotransformation, Oxidation, hydroxylation, dealkylation and sulfoxide formation are examples of…

A

Phase I reactions

41
Q

With few exceptions, the metabolites of drugs are more __________ than the parent drug.
Polar or Non-Polar

A

Polar

42
Q

The primary site for drug absorption is:
Stomach
Small intestine
Muscle
Kidney
Liver

A

Small Intestine

43
Q

Metabolism is the __________ conversion of one chemical substance to another.

A

Chemical

44
Q

This metabolite is highly reactive and responsible for acetaminophen-induced hepatotoxicity:

A

NAPQI

45
Q

The following is an inactive metabolite:
Dihydrocodeine
Delta-9-Carboxy-THC
Morphine 6-glucuronide
11-OH-THC
Nordiazepam

A

Delta-9-Carboxy-THC

46
Q

In contrast to drugs after phase I biotransformation, drugs after phase II have:
Less pharmacological activity and lower water solubility
More pharmacological activity and greater water solubility
Less pharmacological activity and greater water solubility
More pharmacological activity and less water solubility

A

Less pharmacological activity and greater water solubility

47
Q

Cocaine undergoes this to form benzoylecgonine:
Demethylation
Reduction
Hydrolysis
Glucuronidation
Oxidation

A

Hydrolysis

48
Q

Cytochrome p450 is a family of:
Mixed function monoamine oxidase inhibitors
Mixed function glutathione transferases
Mixed function transferases
Mixed function oxidases
Mixed function isozymes

A

Mixed function oxidases

49
Q

True or False: Lorazepam has no active metabolites.

A

True

50
Q

1,4-butanediol is a metabolic precursor to:
GHB
PCP
LSD
GBL
alpha-PVP

A

GHB