CLINICAL PHARMACOLOGY ; GOOD QUESTIONS AND THEIR ANSWERS FOR EXAM REVISION

CLINICAL PHARMACOLOGY ;
GOOD QUESTIONS AND THEIR
ANSWERS FOR EXAM REVISION


Pharmokinetics
what the body does to the drug (absorption, distribution,
metabolism, excretion)
Pharmacodynamics
what the drug does to the body; mechanism of action
Why do we administer drugs intramuscularly?
For drugs with poor absorption (or no IV line)
What routes bypasses the liver(portal circulation)
initially?
Rectal and sublingual
What are the 4 steps of a Pharmacokinetic Study?
Step 1 : dose animal or human

Step 2: collect samples(blood,urine,stool,bile) at various
timepoints

Step 3: analyze it for drugs/metabolites

Step 4: PK data analysis
Distribution is also known as what phase?
alpha phase
Elimination is also known as what phase?
Beta phase

,Why is Tmax important?
It tells us how much time it takes to get the max response.
What is the trough dose/concentration?
Trough concentration (Ctrough) is the lowest
concentration reached by a drug before the next dose is
administered, often used in therapeutic drug monitoring.
4 processes that influence the path of every
medication
ADME
A- absorption
D- distribution
M- metabolism
E- elimination
Absorption is how _____
how the drug enters the bloodstream
Distribution is how ___
how the drug travels in the bloodstream, and beyond, to
the site of action
Metabolism is how ____
How the body breaks down the medication, preparing it for
removal
Elimination is how ____
How the body removes the mediation from the body
What is bioavailability
A measure of drug absorption and the extent of first- pass
metabolism, defined as the fraction of administered drug
that reaches the systemic circulation.
Which option best describes the location of most P450
enzymes?
Liver and GI tract

,True or False? Only drugs that are unbound to plasma
proteins can leave the bloodstream and enter the
tissues.
TRUE
Why would a clinician ask about elimination half-life?
To understand how quickly the drug is removed from the
body

What are A,B and C ?
A - IV
B - IM
C - subcutaneous or oral.iguess XD
Why are nitrates administered sublingually?
to bypass the liver, otherwise most of the drug will be
metbolized and therefore cause no effect
what drug doesnt have a 1st bypass effect?
e.g. ciprofloxacin
What is bioavailability?
Fraction of administered drug that reaches systemic
circulation unchanged.
What is the bioavailability of IV drugs?
100%
Where anatomically are P-glycoproteins mostly
expressed and ehat are their function?
Gut, blood-tissue barriers e.g. BBB and BTB
They keep drugs out via ATP dependent efflux
What factors contribute to the distribution of a drug?
1. Barrier permability
2. Binding to compartments and proteins
3. ph partition
4. Fat:Lipid partition

, Equation for volume of distrubution?
Vd=Ab÷Cp
If a drug has a low volume of distribution, what does
this mean?
Drug mostly confined in blood, highly bound to plasma
proteins/highly hydrophillic
What does it mean if a drug's volume of distribution is
high?
Bound to tissue components/lipophillic
Give one example of drugs with a:
1. low volume of distribution
2.even distribution
3. quite large volume of distribution
1. warfarin
2.atenolol
3. chloroquine
Half life determines what?
dosing interval
Volume of distribution determines what?
loading dose
What is a loading dose?
initial higher dose of a drug that may be given at the
beginning of treatment to RAPIDLY achieve a therapeutic
level
Phase 1 metabolism, name things u know about it lol
Includes CYTOCHROME P450. Reduction, Oxidation,
hydrolysis, dealkylation.

Doesn't change water-solubility.

Happens in ER.