Pharm I Exam I Flashcards
1
Q
What the drug does to the animal is referred to as:
A
Pharmacodynamics
2
Q
What the animal does to the drug (the movement of drugs within the body) is referred to as:
A
Pharmacokinetics
3
Q
T/F: IV administration of a drug is characterized by rapid onset and long duration
A
False
IV administration of a drug is characterized by rapid onset and short duration
4
Q
Acidic drugs ionize in ______ environments
A
Acidic drugs ionize in basic environments
5
Q
Basic drugs ionize in ______ environments
A
Basic drugs ionize in acidic environments
6
Q
Does this graph represent a weak acid or a weak base?
A
Weak base
Weak bases are absorbed from an alkaline environment and sequestered in an acid medium
7
Q
Does this graph represent a weak acid or a weak base?
A
Weak acid
Weak acids are absorbed from an acidic environment and sequestered in an alkaline medium
8
Q
T/F: Facilitated diffusion is a carrier-mediated transport, moves with a concentration gradient, and requires energy for movement
A
False.
Facilitated diffusion is a carrier-mediated transport, moves with a concentration gradient, but does not require energy for movement
9
Q
T/F: Active transport is a carrier-mediated transport, moves against a concentration gradient, and requires energy for movement
A
True
10
Q
Do you care about this dog drawing?
A
No. No you don’t.
11
Q
What is the rate-limiting barrier for absorption of drugs in the skin?
A
Stratum corneum
12
Q
Transfer of drugs from the bloodstream to tissues around the body is referred to as:
A
Drug distribution
13
Q
Chemical alteration of a drug by different body tissues is referred to as:
A
Drug metabolism
14
Q
Most drugs are eliminated via the ________
A
Most drugs are eliminated via the kidney
if a drug is very lipophilic it will be easily reabsorbed (and thus not eliminated)
15
Q
The _______ is the main organ for drug biotransformation
A
The liver is the main organ for drug biotransformation
16
Q
What does ADME stand for?
A
- Absorption
- Distribution
- Metabolism
- Excretion/Elimination
17
Q
How do drugs get across cell membranes?
A
- Passive diffusion
- Facilitated diffusion
- Active transport
- Pinocytosis
18
Q
What does pKa mean?
A
pH at which 50% is ionized and 50% nonionized
19
Q
What percentage of the body is water?
A
- ~57% of the body is water
- 40% of that is intracellular
- 13% is interstitial fluid
- 4% is plasma
20
Q
Weak acids bind to ________; Weak bases bind to _________
A
Weak acids bind to albumin; Weak bases bind to β globulins and glycoproteins
21
Q
What are the two things that can happen to a drug when it is metabolized?
A
Bio-inactivation or bio-activation
22
Q
What are Phase I reactions?
A
- Nonsynthetic - produce more reactive molecules
- Oxidative reactions
- Reductive reactions
- Hydrolytic reactions
23
Q
Which phase reactions involve cytochrome p450 enzymes?
A
Phase 1
24
Q
Name the 3 major enzyme inhibitors:
A
cimetidine, chloramphenicol, ketoconazole
25
What are the 2 main routes of drug excretion?
Renal & hepatic (biliary)
26
What is the primary method of renal excretion?
glomerular filtration
27
How does electric charge affect excretion?
Large, negative charged drugs are repelled by negative charged basal cell membrane protein
28
How does protein binding affect excretion?
Protein-bound drugs can **not** be filtered, therefore can not be excreted
Only unbound molecules can be filtered
29
What is beneficial about active tubular secretion?
Ionized molecules can be transported
30
What type of drugs can be excreted in bile?
Lipid soluble drugs with MW \> 300 and a polar group attached are more easily excreted in the bile
31
What is enterohepatic recirculation?
Conjugates in bile are hydrolyzed in intestine, then the drug is absorbed again. This prolongs the drug's residence time in body
32
What type of drugs undergo ion trapping in milk?
Weak bases
33
What is t1/2?
Half life – time it takes for drug concentration to decrease by 50% (for first order kinetics drugs)
34
What is bioavailability?
The amount of a drug that gets into systemic circulation
35
In order for 2 drugs to be bioequivalent, they must have what 3 things in common?
AUC, Cmax, Tmax
36
If you double the dose of a drug, how much longer will it stay in the body?
1 more half-life
37
What is the equation for volume of distribution?
**Vd = Q/Cp**
Q = dose
Cp = plasma drug concentration (mg/mL)
38
What does it mean if a drug has a large Vd?
A large Vd means that the drug is distributed somewhere outside of the bloodstream (usually fat) and is unavailable
39
What does it mean if a drug has a small Vd?
A small Vd means that the drug is not being saturated to all tissues of the body (Vd \< 1L)
Drugs that remain mostly in plasma with have a low Vd
40
What are different types of drug effects?
Therapeutic, side effect, adverse effect, toxic effect
41
A \_\_\_\_\_\_\_\_ is anything that binds to a recognition site
A **_ligand_** is anything that binds to a recognition site
42
What is a pro-drug? Give an example.
the ‘drug’ needs to be metabolized to be active
enalapril --\> converted to enalaprilat in the liver
43
What is the difference between an ionotropic and metabotropic receptor?
* **Ionotropic** – binding of the drug prevents/allows ions passing through – fast neurotransmission (nicotinic)
* **Metabotropic** – (G-protein receptors) - transduce an extracellular signal to an intracellular one; slow secretory and smooth muscle receptors (muscarinic, Ach, histamine)
44
A(n) ________ mimics the effect of an endogenous ligand
An **_agonist_** mimics the effect of an endogenous ligand
(can be full, partial, inverse)
45
What is an antagonist?
Binds to the receptor but (in theory) does nothing on its own, however it prevents an agonist from binding and thus blocks effects of the receptor
46
What is a **mixed agonist-antagonist**
Acts as an agonist in one type of receptors and as an antagonist on other type of receptors
47
An agent used to enhance renal excretion of weak base drug:
ammonium chloride
48
An agent used to enhance renal excretion of weak acid drug:
sodium bicarbonate
49
T/F: All ganglionic synapses utilize acetylcholine
True
50
\_\_\_\_\_\_\_\_\_\_\_\_\_ are enzymes that break down acetylcholine and are important in stopping the stimulation of the post- synaptic nerve
**_Cholinesterases_** are enzymes that break down acetylcholine and are important in stopping the stimulation of the post- synaptic nerve.
They are membrane bound enzymes that bind acetylcholine and break it into choline and acetate which can then be recycled into more acetylcholine.
51
Mean Residence Time, which describes the length of drug persistence in the body, is utilized in which type of compartment model?
non-compartment model
52
An Alkaloid is derived from which of the following?
1. Plant
2. Animal
3. Bacteria
4. Fungi
**Plant**
53
All of the following are properties of active transport across biological membranes EXCEPT
* It requires cellular energy
* It needs a carrier protein molecule
* It moves against concentration gradient
* It is generally specific
* It is not a saturable process
**It is not a saturable process**
54
Biotransformation of drugs is increased by the following EXCEPT
* Distribution
* Lipid solubility
* Oral administration
* Enzyme induction
* Decreasing the dose
**Distribution**
55
Which of the following statements concerning plasma protein binding is true?
* It is increased in the neonate
* It increases the volume of distribution
* Extensive protein-binding (\> 80%) increases half-life
* It increases systemic bioavailability
* It is an irreversible process
**Extensive protein-binding (\> 80%) increases half-life**
56
A competitive pharmacological antagonist is
* a drug that binds irreversibly with the receptor
* a drug that has affinity and intrensic activity
* a drug that can be displaced by the agonist from the receptor
* a drug that alters the structure of the agonist
* a drug that has affinity but small efficacy
**a drug that can be displaced by the agonist from the receptor**
57
Which type of drug transport is not concentration dependent?
* Pinocytosis
* Simple diffusion
* Facilitated diffusion
* Active transport
* B & C
**Pinocytosis**
58
What is correct regarding the blood-brain barrier?
* Water soluble drugs cannot cross.
* It does not require the use of carrier proteins for transportation of drugs.
* Meningitis decreases the rate of penetration.
* Lipid soluble drugs cannot penetrate.
* It is not susceptible in the newborn.
What is correct regarding the blood-brain barrier?
* **Water soluble drugs cannot cross**.
* It does not require the use of carrier proteins for transportation of drugs.
* Meningitis decreases the rate of penetration.
* Lipid soluble drugs cannot penetrate.
* It is not susceptible in the newborn.
59
Plasma protein binding:
* Decreases the half-life of the drug.
* Generally is not reversible.
* Acidic drugs bind mainly to glycoproteins and lipoproteins
* Basic drugs bind mainly to albumin
* The bound form is inactive, not distributed, metabolized or excreted by glomerular filtration.
**The bound form is inactive, not distributed, metabolized or excreted by glomerular filtration. **
60
The doctor orders an IV medication to run over 5 hours. It comes in a 1L bag of 0.9% sodium chloride. The medication contains metoclopramide 6mg/2mL. The drop factor is 15gtts/mL. How many mL/hr should we infuse?
* 40mL/hr
* 55mL/hr
* 180mL/hr
* 250mL/hr
* 200mL/hr
**200mL/hr**
61
T/F: Cats are deficient in glucuronyl transferase
**True**
62
T/F: Older animals tend to have reduced cardiac output and hepatic blood flow, which could affect dosage of and response to a drug
**True**
63
T/F: The BBB in younger animals tends to have a lower permeability than in older animals
**False – Young animals have increased BBB permeability**
64
T/F: Idiosyncrasy of a drug is dependent on the dose administered to an animal
False – Not dependent on the dose
65
Are NSAIDs an example of weak acid drugs or weak base drugs?
**Weak acids**
66
When one drug reduces the concentration of the other at its site by interfering with ADME process, this is called:
**Pharmacokinetic antagonism**
67
T/F: The higher the lipid solubility of a drug, the faster it crosses cell membranes
**True**
68
Birds lack oxidative enzymes and are the ONLY animals to use \_\_\_\_\_\_\_\_ as conjugation substance
Birds lack oxidative enzymes and are the ONLY animals to use **_ornithine_** as conjugation substance
69
The volume of distribution (Vd) of a drug is higher when the drug is:
* a strong acid
* a weak acid with a low pka value
* a weak acid with a high pka value
* a weak base with a low pka value
* a weak base with a high pka value
**a weak base with a low pka value**
70
Phenylbutazone, a weak acid/enzyme inducer:
* is excreted in milk in relatively high concentration
* its distribution is decreased in systemic acidosis
* is rapidly excreted in urine in dogs
* its renal excretion is enhanced by administration of ammonium chloride
* its renal excretion is enhanced by administration of sodium bicarbonate
**its renal excretion is enhanced by administration of sodium bicarbonate**
71
\_\_\_\_\_\_ is the plasma concentration of the drug when the maintenance rate of the drug administered is equal to the rate of elimination.
Steady-state plasma concentration (Cpss)
72
Diffusion of most drugs across a membrane is mostly dependent upon what?
Blood flow
73
\_\_\_\_\_\_\_\_\_\_\_ is an acute form of tolerance
**Tachyphylaxis**
74
Which route of administration bypasses the absorption process?
**IV (intravenous)**
The "absorption" phase is the time it takes to inject the drug. Usually IV injections are made quickly so that the plasma concentration reaches an almost instantaneous peak and rapidly declines as the drug is distributed to other tissues
75
What is the most important factor involved with drug absorption for oral medications?
**Surface area of the gut available for absorption**
(diseases like gastroenteritis, neoplastic infiltration, or villus atrophy can significantly change the surface area)
76
In cows with mastitis, the usual route of drug administration is \_\_\_\_\_\_\_\_\_\_\_\_\_
In cows with mastitis, the usual route of drug administration is **_intramammary_**
77
T/F: Drugs that are not in solution or some sort of emulsion are safe to be given intravenously
**False!**
78
What is the pH of plasma?
7.4
79
What is the pH of gastric contents?
2
80
T/F: Only the ionized form of a drug can cross cell membranes
**False.**
Only the un-ionized form of a drug can cross the cell membrane. It will diffuse down the concentration gradient to the other side of the membrane where most of it will become ionized (and thus trapped)
81
T/F: P-glycoprotein is an important protein present in cell membranes that pumps foreign substances out of cells. However, it is not present in the BBB
**False.**
P-glycoprotein is an important protein present in cell membranes that pumps forwign substances out of cells. It **_is present in the BBB_**
82
Metabolism usually inactivates a drug. The exception to this is:
**prodrugs**
need to be metabolized to become active
83
What is the most common metabolic phase II reaction?
**glucuronidation**
Catalyzed by glucuronyl transferase (except in cats, who lack this enzyme); acetylation of acetyl CoA; and methylation by S adenosyl methionine
84
\_\_\_\_\_\_\_\_\_ receptors act to alter gene transcription and thus protein production
**_nuclear_** receptors act to alter gene transcription and thus protein production
85
The ________ is the concentration at which a drug produces 50% of its maximal effect
**EC50 **
This only applies to *in vitro* preparations.
Just a heads up: EC50 and ED50 are NOT the same thing. ED50 is the dose at which a drug produces a quantal response in 50% of animals
86
The _______ is the dose that kills 50% of animals
The **_LD50_** is the dose that kills 50% of animals
87
This is not a question, but just remember that in zero-order kinetics, a certain **amount** of drug is eliminated per time, regardless of what the drug concentration is. When plotted out, you would get a straight line
88
As Vd increases, t1/2 \_\_\_\_\_\_\_\_\_\_
As Vd increases, t1/2 **_increases_**
89
As Vd decreases, t1/2 \_\_\_\_\_\_\_\_\_\_
As Vd decreases, t1/2 **_decreases_**
90
As Clearance increases, t1/2 \_\_\_\_\_\_\_\_\_\_
As Clearance increases, t1/2 **_decreases_**
91
As Clearance decreases, t1/2 \_\_\_\_\_\_\_\_\_\_
As Clearance decreases, t1/2 **_increases_**
92
Which of the following agents can be used to enhance renal excretion of aspirin, a weak acidic drug, in cats?
* atropine
* ammonium chloride
* epinephrine
* sodium bicarbonate
* methionine
**sodium bicarbonate**
93
T/F: A drug's volume of distribution (Vd) is a good indication for the ability of drug to diffuse across membranes.
**True**
94
T/F: If the intravenous infusion rate is doubled, the time needed to achieve a steady-state plasma concentration is doubled.
**False**
95
T/F: For most drugs, the half-life (t1/2) depends on the dose of drug administered.
**False**
96
T/F: The MOST common biotransformation reaction is oxidation.
**True**
97
T/F: Facilitated diffusion of drugs is a carrier-mediated transport that requires energy
**False**
does **not** require energy
98
T/F: Generally, drugs that bind extensively to plasma protein tend to have short half-lives
**False**
99
Which of the following is the rate-limiting step that controls the rate of absorption of a solid drug given orally?
* a - dissolution
* b - lipid solubility
* c - degree of ionization
* d - stability
c - degree of ionization
100
A drug that counters the effect of another drug by binding to different receptors and causing opposing effects is called:
noncompetitive antagonist
101
T/F: Urinary acidification increases the excretion rate of NSAIDs such as aspirin
**False**
102
T/F: The volume of distribution (Vd) of a drug can be used to calculate the amount of drug needed to achieve a desired plasma concentration.
**True**
103
A drug with a half-life of 8 hours is administered by continuous intravenous infusion. How long approximately will it take for the drug to reach its desirable steady-state level?
* 10 hours
* 20 hours
* 30 hours
* 40 hours
**40 hours**
104
Which of the following is a phase I drug-metabolizing reaction?
* glucuronidation
* acetylation
* sulfation
* hydroxylation
**hydroxylation**
