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Flashcards in Pharmacology Deck (42):
1

Specificity

Ability of a drug to act thru a single mechanism of action

2

Selectivity

Ability of a drug to induce one effect in preference to another

3

Standard Safety Margin

LD1-ED99/ED99 X 100

What kind of number would you want to have?

4

Tachyphylaxis

Acute form of drug tolerance induced by rapid, repeated administration of a drug

5

Potentiation

One drug used in combination with another does not have any effect but potentiates the effect of the other

6

Isoniazid Toxicity

Prevalent in Scandinavians, Jews, and White North Africans; is due to slow hepatic arylamine N-acetyltransferase Type II

7

Response Theory

The theory that the magnitude of a response is dependent upon the rate of formation of a D-R interaction

8

Polymorphism effects on Biotransformation (Pharmacokinetic)

Can change the Vm or Kmax; CYP3A5*1 allows people of African descent to metabolize some drugs faster

9

CYP2B6 polymorphism

Causes cyclophosphamide failure

10

CYP2C9

Causes increased risk of bleeding and faster metabolizing of Warfarin

11

Efficacy

The maximal effect produced by a drug

12

Phase I & II enzymes

I => Breaking down (hydrolysis, oxidation)

II=> Addition (Conjugation)

13

Pharmacokinetic Polymorphisms

Lead to changes in Km or Vmax

14

Gilbert's Syndrome

Polymorphism in UDP-glycosyltransferase (Phase II enzyme)

Causes Irinotecan toxicity

15

Polymorphisms

Alter drug receptors in diseased states

E.g. - Methemoglobinemia in G6PD deficiency due to faulty Dapsone

16

Signal 3

Promotes the differentiation of effector T-cells and is transmitted via cytokines

17

IL-6

Forms Th17 cells that secrete IL-6 and IL-17

18

IL-4

Forms Th2 cells that secrete IL-4 and IL 5

*Mediates changes via GATA-3

19

INF-y

Promotes Th1 cells that secrete INF-y and IL-2

Also secrete IL-1, IL-12 and TNF-a

*Mediated by T-bet

20

IgM to IgE

IL-4

21

IgM to IgG

INF-y

22

IgG to IgA

TNF-B

23

Alcohol and Aspirin kinetics

Zero Order (Chronic Aspirin use only)

24

Bioavailability

F= AUC(oral)/ AUC(iv)

Studies on this determine effects of food on drugs

25

Drug Half Life

t^1/2= .693/ke

ke= elimination constant

26

How long does it take to eliminate a drug from the body?

4 half lives

-by this point, only 6.25% remains

27

Volume of Distribution

Vd= Dose(iv)/Co

Volume of a drug distributed in the body once an EQUILIBRIUM has been established

If Vd>TBW, drug has been deposited somewhere and is highly lipophilic

28

Clearance Equation

CL= Ke X Vd

CL= 0.693 X Vd / (t^1/2)

29

How long does it take to achieve Css?

4 half lives

30

Maintenance Dose

MD= Dose X F/ Dosing interval (t)

31

Css using Maintenance Interval

Css= MD/CL

32

Loading Dose

A single large dose achieves Css and MD are reapplied in the future

Css= Loading Dose X F / Vd

What formula is this a rearrangement of?

33

First Pass Elimination Effect

When a drug passes thru the hepatic circulation from the GI tract and is mostly metabolized

34

If you have an orally labile drug, what might be a better alternative for administration?

Intramuscular

35

When is intraarterial administration primarily used?

Cancer chemotherapy

36

Microsomal Enzymes

Consist of mostly Phase I enzymes; includes CYP enzymes and their substrates must have lipophilic character

*Activity is INDUCIBLE (smoking, drinking, exercise)

*Located primarily in the smooth ER

37

CYP1A2

Includes Warfarin; smoking increases the metabolism of Warfarin via this pathway

*Can be inhibited by GRAPEFRUIT JUICE

38

CYP2E1

Microsomal enzyme whose Activity is induced by ethanol and increases the metabolism of Acetaminophen by the liver

39

Non-microsomal enzymes

Mostly phase II enzymes that are Phase II enzymes (acetylation, sulfation, methylation)

*Activity generally is not inducible; enzymes are found in the cytosol

40

Enterohepatic cycling

Process by which a drug or metabolite is excreted thru the biliary ducts but is reabsorbed by the distal SI; leads to an increased half-life

41

Freely filtered drugs at the glomerulus

Drugs w/ a MW that is

42

VKORC1

Activates Vitamin-K; inhibited by Warfarin