Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharmcology > lecture 5 > Flashcards

lecture 5 Flashcards

1
Q

tissue perfusions 1 phase

A

-liver
-kidney
-brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

second distribution phase

A

muscle
viscera skin
fat (slower)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

diffusion of the drug into the interstitial fluids

A

occur RAPID and because highly permeable nature of capillary endothelial membrane (except brain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

distribution

A

partitioning of drugs between BLOOD and the TISSUE

Determinants- transmembrane pH and the lipid solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

tissue binding :

“depot” definition

A

drug is BOUND in tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or false: Drugs in TISSUE are in higher concentrations than Drug in EXTRACELLULAR FLUID

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

example of slide 6: Quinacrine (anti-malaria)

A

conc in LIVER is several thousand more times than in BLOOD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

TISSUE BINDING

A

occurs in cellular constituents - proteins, phospholipids, nuclear protein and are REVERISBLE

**CAN produce local toxicity, as in the case of “amino glycoside, antibiotic gentamicin” (in kidney)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

amino-glycoside antibiotic gentamicin (in the kidney )

A

produces a local toxicity because of tissue binding or accumulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

many lipid soluble drugs are stored in

A

NEUTRAL FAT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in obese people the fat content of the body is as high as

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

bone

A

*tetracycline antibiotic
metal ion chelating agents and heavy metals can accumulate in the bone by absorption into the bone crystal surface and eventual incorporation into a crystal lattice.

Bone can be a reservoir for toxic agents- radium and lead in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Redistribution

A

Termination of drug effect- is done by metabolism, excretion, and redistribution.

redistribution of drugs from its site OF ACTION into OTHER SITES/TISSUE

  • specifically terminates highly lipid-soluble drug that acts on the brain or cardiovascular system (INJECTIONS /INHALATION)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

bbb

A

lipid solubility, non-ionized, unbound

the drug should be very LIPOPHILIC - to cross the bbb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Distribution

A

Some barriers restrict flow into the CNS- BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

BBB

A

the brain has capillaries that cannot seep between cells (paracellular transport), and must be transported transcellular.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

choroid plexus

A

where the CSF is formed, and has a TIGHT JUNCTION BARRIER, epithelial in nature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what kind of drugs make it into the CNS ?

A

Lipid soluble and non-polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Inflamed BBB

A

will enahcne the permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

transport fro CSF to blood

A

ACTIVE TRANSPORT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

BBB we can use it for drug design

A

to limit ACTION OF PERIPHERY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

PLACENTAL TRANSFER

A

DRUGS TRANSFER TO THE FETUS
** Fetus plasma SLIGHTLY more acidic than mother, 7-7.2 compared to 7.4, ION TRAPPING OF BASIC DRUGS OCCURS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Volume of Distribution (Vd)

A

**APPARENT -measure
theoretical and practical significance

amount of drug in the body to the concentration of drug in plasma or blood.

Vd= amount of drug in the body (mg)/ conc mg/L

DOSE/ conc in blood (at steady state
mass/density-volume

Vd can EXCEED THE actual volume of biological system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
A

If the volume of distribution (Vd) exceeds the actual volume of blood, it means that the drug is not confined solely to the bloodstream, but has distributed itself into tissues, organs, and other body compartments beyond the blood.

In this scenario, the drug is distributed throughout the body, not just in the bloodstream. This could mean that the drug has entered tissues, cells, or other compartments where it can exert its pharmacological effects or be metabolized and eliminated.
If the Vd is large, it suggests that the drug has a widespread distribution throughout the body and may have a longer duration of action or a larger area of effect.

This could be due to factors such as the drug’s molecular size, lipid solubility, binding to proteins or tissues, or other pharmacokinetic properties. A large Vd may also indicate that the drug is extensively distributed into tissues and organs, which can affect its pharmacokinetic profile and therapeutic efficacy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
total body of water
0.6 L/kg
26
extracellular water
0.2 L/kg
27
28
bone
0.07 L/kg
29
blood
0.08 L/kg
30
plasma
0.04 L/kg
31
Fat
0.2-0.35 l/KG
32
small water-soluble molecule
Ethanol- 37 L
33
LARGE WATER SOLUBLE MOLECULES
gentamicin- 18L
34
STRONG PLASMA protein bound molecule that is LARGE
heparin- 3.4 L
35
highly lipid soluble molcules
DDT
36
certain ions
fluoride
37
Vd is large distribution
IS GREAT
38
Vd is small distrution
LIMITED
39
CLEARANCE
Ratio rate of elimination by GI LIVER AND KIDNEY/ CONCENTRATION in the fluid-like blood renal is kidney determine for RENAL and Liver, GI, Respiratory Sweat
40
Cl=
rate of elimination/ conc
41
RATE of elimination
Conc x Clearence
42
total systemic clearance is
summing up all. the clearances of each process like Cl renal +Cl liver
43
clearance
remains constant and FIRST-order kinetics rate of drug removal/ conc rate of removal: mg/ min conc: mg/mL clearance- ml/min *clearance is the volume if fluid or blood that would need to be completely free of all drugs to account for elimination * as the drug concentration of drug increase the rate of elimination will also increase BUT Clearance is remains sam
44
variable clearance
is FIRST ORDER *we can find clearance in a first oder by estimating the AUC clearance= dose(conc(/ AUC
45
Constant clearance
is zero order (clearance remains same as we increase CONC and elimination)
46
main factors in renal excretion-1
glomerular filtration- tells us the fraction of free drugs compared to the protein-bound drug , when the drug is strongly bound to protein it DOES NOT FILITER
47
main factors in renal excretion- passive tubular reabsorption
enhanced lipid solubility favors reabsorption, lipid-soluble readily cross renal tubular epithelial to enter pericappilary fluids ex. thiopental, highly lipid soluble and completely reabsorbed and unchanged drug excreted in urine
48
high concentration of drug causes
elimination to be saturated - called "capacity limited elimination"
49
examples of capacity limited elimination
phenytoin, ethanol, aspirin
50
capacity limited elimination
rate of elimination INDEPENDENT FROM CONC so the clearance will FALL
51
OTHER NAMES FOR CAPACITY LIMITED ELIMINATION
conc/dose dependent (high conc) saturable non-linear Michaelis menten kineitcs elimination
52
capacity limited kinetics
a constant amount of drug is eliminated per unit of time vs constant fraction of drug eliminated per unit of time a state state conc cannot be reached
53
rate of elimination
= vmax x c/ km + c km- drug conc at which elimination half Vmax vmax- max elimination capacity
54
flow-dependent elimination
cleared rapidly by the organ (liver will metabolize drug completely) clearance depends on blood flow (where the rate of drug delivery to the organ or liver) high extraction drug
55
neonates clearance
they have reduced hepatic metabolism and renal excretion, organ are immature still
56
clearance elderly patients
differences in absorption, hepatic metabolism, renal clearance and vol distribution
57
genetic factor-clearance
genetic polymorphism affects- CYP.... 2D6 2C19 2A6 2C9 N-acetyltransferase which have significant differences in drug metabolism abilities
58
half life
time interval after which conc is half at the beginning time interval constant throughout the dosing interval or time interval observed - ONLY meaning in first order time required to eliminate 1/2 of the total amount of drug in the body usually the constant rate of elimination one t 1/2 will reduce drug in the body by 50% useful to identify steady states Means for estimation of appropriate dosing interval
59
1 half life - 6half lives
1-50 2-25 3-12.5 4-6.25 5-3.12 6-1.56
60
approximately 4 half-lives are required to reach
about 94% of a new steady-state
61
t1/2 = (0.693 · Vd)/CL
(0.693 · Vd)/CL
62
Factors affecting t1/2:
disease states-- affects the volume of distribution and clearance acute viral hepatitis alters the plasma and tissue it DOES NOT change volume but increases clearance because more free drug (not bound to protein).
63
accumulation factor
accumulation factor = 1/ fraction lose in one dosing interval When drug doses are REPEATED the drug accumulates in body until dosing stops if the dosing interval is SHORTER than 4 half-lives (a week) then the accumulations will be detectable
64
loading dose
is used to produce a therapeutically effective blood level without delay loading dose makes a larger initial dose
65
66

Pharmcology (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions