Practice exam that covers all material learned in PHAR121 module 2. Answers are included. Use it as a summary or take the curated questions to quiz yourself and study with active recall.
PHAR 121 Module 2 Exam
Module 2A – Basic Pharmacological Concepts
(LO) Define ED50, TD50 and the dose-response relationship 50% of of patients >
standard/average close
a
group
-
·
ED50 : Median effective close -
close required to present expected therapeutic response in
50 % of > LD in pre-clinical data + extrapolated - hum
adverse effects/produce toxicity in a
group of patients
-
to cause
TD50 : Median Toxicity close-close required
·
Dose-Response is how an individual
affected by drug
is
responding to the close they were
given
Phase 1 : very few target cells
Phase 2 : Shows linear relationship between amount of
drug administered and response obtained - close-response relationship-linear-predictible
Phase 3 : plateau -
no more response /increase inclose
-
can see adverse effects even if no response
(LO) Draw a plasma concentration vs. time curve. Label and define onset, intensity, duration,
and therapeutic window.
Itoxic /Supratherapeutic
-------mensity
- - - -
(LO) Differentiate between therapeutic window (TW), therapeutic range (TR), and therapeutic
index (TI)
required for therapeutic effects a patient
get drug plasma
to the In
·
TW : close concentration in
range
·
TR : describes close needed to
get to Tw in a population
↳ cose are based on a sample of poph
ranges
toxic plasma concentration vs effective plasma concentration
(index-ratio) describing
ratio .
·
TI :
JED50
lots of room between toxic effective
↳ Wide TI
+
:
:
TD50
and effective
↳ Narrow TI : not a lot of room between being toxic
being
(LO) What is the goal of a dosage regimen? Define and analyze all the elements of dosage
regimens: Attain and maintain Therapeutic concentrations effectively treat condition to a
Therapeutic Window , Range ,
and Index are all important elements of a
dosage regiment
close : Sometimes wait 5-7 the to reach
Steady State concentration (Css)
loading dose is
given
to attain therapeutic
Loading
can't
-
we
concentration
[7 Volume of distribution CinerxVd
cose-therapeutic
Loading
·
=
S F
drug bioavailability
.
Salt active -
Maintenance dose : how we Therapeutic concentration (influenced by
maintain the
excretion)
Steady State [] ·
Systemic Clearance Css Els
Maintenance Dose
·
= =
salt active
drug bioavailability S F
.
.
possible most
> we want
-
to plateau as much as In cases
(LO) What are the determinants of a dosage regimen that need to be considered when creating
a dosage regimen for a patient?
3
. Pharmacokinetics
1.
Activity Toxicity
yapeutic window
-
multiple drug Therapy adherence
-
route of administration -
drug interactions
convinience of
regiment
-
(LO) Define:
absorp
Absorption: Drug moving from administration site to
Systemic
circulation (blood) i. e
. movement
tells us about its onset of action
to blood (injected to blood ,
no
-
No
change happens to itself-rate of absorption of
drug drug
Most need to be absorbed to work
drugs
-
SDistribution: 3
·
Ka : absorption rate constant
available at site of action
f: bioavailability amount of
drug
-
·
Cmax : Maximum concentration reached
·
Tmax : time at which Cmax occurs
between circulation and the tissue
A constant equilibrium -
reversible transfer of
drug systemic
Biophase : Site of effect of
drug
-
a
NO ABSORPTION INTO TISSUES-REVERSIBLE EQUILIBRIUM (E)
have to be distributed to work
drugs
-
E
drug-tells drug is
3
·
Vd : volume of distribution -
visual representation of how much fluid It takes to distribute a us how much
extent of distribution from blood to Vd-distributed widely
available at tissues -
tissues-large
fulb) : fraction unbound-amount bound to DISTRIBUTION PROPERTIES relate
of
drug not
·
to
proteins like albumin > creates complex > -
prevents
-
-
body composition (adipose
tissue perfusion
and inability to cross plasma membrane
binding
-
Cu/Cu Cu/Crotal binding
-
-
expressed as a %: Fulb) = +
CD =
,Elimination : metabolism + excretion
from
-
drug body
Irreversible removal of
circulation
begins drug reaches Systemic as soon as
-
>
Drug
concentrations are
always changing-distributing eliminating
- -
↳ needs to be considered in elimination
Metabolism: Irreversible removal of
drug by
chemical conversion to Inactive metabolite
(drugt enz =
metabolite
-
biotransformation
I
drug to inactivate It or make it for excretion
more
likely
Excretion: Irreversible removal of intact/parent drug
Drug leaves body
(LO) Differentiate between pharmacokinetics and pharmacodynamics and describe their
relationship: ! PK drug Cp drugs ! assumes there is a relationship between and at receptor site
3
PK :
drug movement in the
body study (ADME)
+
of time-course
allows us to predict drugCp wout starting from Scratch every time Response (PD) Distribution
-
occurs at
primary secondary and derived parameters
-
, ,
PD : What
drug is doing to the
body what is
happening at
drug-receptor
-
(LO) Analyze the primary, secondary, and derived PK parameters and describe their
relationships
Primary all derived by physiology all constants that don't
change In linear PK conditions
- -
S 3
1 K
.
a absorption rate-determined by blood frow at abs site ,
gastric eptying Gastrointestinal tube (GIT) motility
,
acid enzymatic activity
.
2
F-oralbioavailability-gastric emptying ,
secretion , , GIT
motility -
amt availible orally at SOA
3 CIR-renal clearance
. determined by renal blood flow , fulb) Urine PH and flow , Secretion/reabsorption
glomerular filtration active
-
,
,
4
. CH-hepatic clearance -
by hepatic blood flow full) intrinsic clearance
determined , ,
. Vd-volume of
5 tissue perfusion
distribution determined by fulb) Tissue binding
-
body composition and , ,
size ,
partitioning
Secondary-determined by primary parameters
S 3
1. Elimination half life (t" 2) : tl =
10 .
693 .
Derived-various descriptive parameters calculated and used to make clinical decisions
S
Area Under Curve (AUC I v) AUCir cose/CIs
S
1 : assess extent of exposure to IV
drug
=
.
.
2 Steady State Concentration (Css) to consider infusion pumps : within the equation Css Infusion rale/CIs =
. Area Under Curve Oral (AUC) : assess extent
of exposure to oral
drug AUCo close F/CIs
=
3
.
time lose
Plateau Concentration Oral (C) assess trends in concentration over F
Average
=
4.
.
:
CI dose interval
5. Tmax (max : Visual inspection of Cpvs .
t to compare to therapeutic window
,
(LO) Describe the different transport mechanisms that exist across polarized epithelia
S
and the polarized epithelia decide what Paracellular : pass
Transporters enzymes
in
gets across
through intercellular space between cells
Passive Diffusion : concentration
gradient-uses no
energy
= Transcellular :
transportation through the cell
a .
movement
by
-
molecules must be small , non-ionized and lipid soluble transport depends on Size , ionization and
solubility of the
drug
. Endo
b Exocytosis vesides that
moved via transport
and :
drugs them
-
c .
Carrier-Mediated :
energy dependent pathway typically
used by small
hydrophilic drugs
Active Transport requires ATP as an energy source
i
. :
ii. Facilitated Transport via transport protein
:
What are frequency distribution curves?
at different closes
Graphical representation showing the number of patients
responding to a
drug during Clinical trials
↳ follows normal distribution
Binary-shows whether a certain response occurred or not
Does the ED50 apply generally to everyone? Why or why not? How do we compensate for this?
Averagedose does not apply to
everyone
We use ED50 as a
starting point then
adjust accordingly
In a dose-response relationship, there comes a point in the curve (phase 3) where there is no
further response with higher dose. Explain.
There theories that exist as to the plateau
are
why occurs :
E
left for bind to so it no
-
all receptor sites have been filled and thus there ,
is
nothing drug to longer elicits a response
↳ -
keep
no more
In
relief
mind
or response is possible after
that even
though
there is
a
no
threshold
further response
is reached
,
toxicity
can still occur
, What is the goal of dosage regimen? When do we normally reach this goal?
Attain and maintain therapeutic concentration to treat a condition
effectively
to reach steady
of same close to reach Css L keep therapeutic window-goalState
is
Normally
drug 5-7 te
at of in
[J : Css
When would a loading dose be required? Explain
When we can't wait 5-7 t to see a response
someone wlanaphalaxis
eg.
Describe the loading dose equation and explain each of its components and how it contributes
to the overall formula LD dependent components is on these
compensate ↑ to
Ciner therapeutic [] ↑, LD has to
if the
3
CinerxVd LD close :
LD
loading
= =
Vd : If the volume of distribution increases , LD M for the ↑
must in
SxF Ciner =
therapeutic concentration more volume
distribution through that is active increases , LD can decrease
Vd =
volume of distribution S : If the
drug
fraction of
Increases LD can decrease
bioavailability drug
of
S =
salt formation ↑ if ,
F =
bioavailability
Which PK property is maintenance dose impacted by the most? Explain
Elimination metabolized excreted
Since
drugs that are are no
longer able to contribute
to maintenance of therapy > more
-
closes need to be added to maintain/reach therapeutic
effects
Describe the maintenance dose equation and explain each of its components and how it
contributes to the overall formula
State [7 depends of MD and Cls
Css MD Cs I Steady
D R
= =
at
-
if MD increases then this means
we need more to stay
Increases
drug
thus steady state concentration
effects
same therapeutic ,
cleared from
-
if Is increases this means
drug is being systemic
state [7 Overal
this decreases steady
circulation at a
higher rate -
Differentiate between linear PK and non-linear PK
Linear proportional to concentration (Cp) > predictable
drug close dreg plasma concentration (Cp)
-
PK : is
proportional is not - not predictable
dose
drug
to
Non-linear PK
drug : plasma
Why do we need PK?
-
Allows us to
predict Cp wout
starting from scratch
predict Cp individuals
-
use formulas /many variables to in
Some variables come from the variables come from the patient
drug some
-
,
What are some adjustable elements of the dosage range that can determine the ‘shape’ of a
[plamsa] vs. time curve? What factors are related to drug effect?
Factors related to
drug (based 10PK parameters)
Adjustable Elements effect
: on :
of Administration
Route Cmax
-
-
Interval Tmax
Dosing
-
-
-
Formulation
-
AUC
t'l2
Amount of
Drug
-
-
-
Css
-
TW
Reiterate the four parameters that describe absorption:
- Ka absorption : constant rate
- F bioavailability at site drug action
: of
- Cmax Maximum concentration drug at receptor
Site
:
of
- Tmax time which Cmax occurs
: at
Reiterate the two parameters that describe distribution:
- Va volume distribution larger
:
its distributed
of widely how
-
# means
-
much volume is needed to distribute a
drug
available
↳ tells
drug tissues
us how much is at
-fulb) : fraction unbound-tells
you
how much of
drug
is available for
binding
at
binding site
fulb) =
2 x100 %
Cu + Cb
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