pharmacology principles

Question 1

Pharmadynamics

The action of the drug on the body

Answer 1

Receptor interactions
    - agonist/antagonist 
    -affinity or selectivity
  Dose response Curve
     effective dose in 50 nrats
     toxic dose in 50 rats
MOA- Mechanism of Action
Toxic action-adverse reaction/serious SE above toxic dose

Question 2

Therapeutic Window

Answer 2

Between the effective dose and toxic dose

Question 3

Therapeutic Index

Answer 3

Effective Dose
_________________ = Therapeutic Index
Toxic dose

TI score closer to 1 = more dangerous

Question 4

Side effect

Answer 4

Unintended effects when dosage in therapeutic range

Question 5

Potency

Answer 5

Amount of drug needed to produce a response

Effectiveness

Question 6

Pharmacokinetics

Absorption Metabolism
Distribution Elimination

Answer 6

The body’s action on the drug

Question 7

pharmacodynamic

Answer 7

drug profile remains unchanged throughout a persons lifetime ( what the drug does to the body

Question 8

pharmacokinetics

Answer 8

changes with aging etc ( body response to drug)

Question 9

Cipro vs Rocephin

Answer 9

Cipro given PO ( lipid soluble)

Rocephin given parenthaly (water soluble)

Question 10

Absorption

Bioavailability- amount of drug reaching
circulation ( Crestor =lower dose for effectiveness)

Answer 10

Factors which affect
GI tract (lipid soluble-resists stomach acid)
Molecular weight

Question 11

Absorption

CMAX

Answer 11

Maximum concentration per dose

Question 12

Absorption

TMAX

Answer 12

Latency time required for effective dose

Question 13

AUC

Area Under the Curve

Answer 13

Amount of drug in bloodstream

graph represents plasma blood concentration and time

Question 14

Protein Binding

Coumadin interacts with highly bound medication

Answer 14

half life
no kidney excretion (secondary to protein)
> potential for drug to drug interaction

Applicable to long, intermediate and short acting insulin

Question 15

Coumadin interaction with high protein binding medications

Answer 15

they compete for protein binding- coumadin has low affinity for protein–loss of competition with medication for protein binding–>increased amount of unbound coumadin (binding inactivates)–>coumadin in bloodstream=increased coumadin level

Question 16

1st pass effect
Only affects PO medications
cannot be given po route if > 1st pass effect

Answer 16

Drug metabolized before reaching the bloodstream GI – Liver

Question 17

Distribution

Volume of Distribution Vd

Answer 17

plasma concentration or amount of drug in body

Question 18

Vd

Factors effecting

Answer 18

Blood flow                  Protein level
Solubility                    Aging
Hydration                    Organ size
Special Tissues -Meds sequestered 
    fat -estrogen, vitamin D
    bone- Boniva

Question 19

Vd with aging

Answer 19

< amount of body weight as water
< lean muscle mass (20%)
>amount of body weight as fat
< kidney weight
<hepatic bloodflow

Question 20

Distribution

Answer 20

Frick”s Law (Passive Dissusion)
Movement from > concentration to < concentration.
Types
Aqueous/ Lipid Diffusion
Carrier Transport
Endocytosis/pinocytosis -engulfing particles or H2O

Question 21

Clearance

Answer 21

Rate that drug is completely removed by biotransformation/excretion.
renal -H2O soluble
hepatic-fat soluble

**Protein bound drugs cannot be excreted from kidneys.

Question 22

Biotransformation

Answer 22

Imitrex
100mg po or 6mg SQ
Biotransformation of medication is changed by route of administration.
1st pass effect

Question 23

Metabolism

Answer 23

Occurs in liver by Cytochrome P450 System.

47% CYP3A4

Question 24

Metabolism

Phase I Reaction

Answer 24

Phase I- Oxidation, reduction,deamination, hydrolysis.
changed to water soluable
P450 enzymes

Question 25

Metabolism--Phase II Reaction acceleration of excretion inactivation of drug >effectiveness (codeine becomes morphine) activation of Prodrugs (inactive before liver metabolism)

Answer 25

conjugation of molecules naturally present in body to the drug molecule. can happen p Phase I

Question 26

Parent Drug ----Metabolite | Liver conversion

Answer 26

Amitriptyline--nortriptyline Codeine---Morphine Primidone--Phenobarbital==< toxicity risk Valacyclovir--acyclovir

Question 27

Valproic acid--St John Wart Reaction

Answer 27

Substrates are metabolized by the same family Substrates are metabolized by the same family St John's Wart is an inducer (makes metabolism family work better and faster)---Depakote is metabolized faster---< TMAX (drug leaves system quicker)-

Question 28

Coumadin --Cipro interaction

Answer 28

Cipro inhibits warfarin--accumulationwith same dosage--->AUC-->INR

Question 29

Vicodin-Tylenol-ETOH

Answer 29

Vicodin increases effectiveness of tylenol. Beer is a P4502E1 inducer and tylenol is its substrate---increased metabolism--decreased AUC. Tylenol becomes a liver toxin with metabolism---when inducer causes increased metabolism (ETOH)--increase liver toxins--liver toxicity

Question 30

ST John's Wart | common drug interactions

Answer 30

Cyclosporine (anti rejection)--can be life theratening Digoxin--decreased digoxin levels day 10 HIV drugs Antivirals -(-Indinavir) monitor closely for reaction > viral load < AUC 57%

Question 31

Grapefruit Juice ``` ***** Carbamazepine Increased AUC (peak, trough) Amiodarone Increased AUC 50% Increases concentration 40% Increased peak plasma concentration 84% ```

Answer 31

``` Flavonoid glycosides (green tea) Inhibitor of CYP1A2, and CYP3A4 (intestinal level) ``` Avoid Tegretol, estrogen, CCB (ipine), buspar, select statins (Not zocor or crestor), diazepam, zoloft,Geodon (ziprasidone)

Question 32

Cipro (CYP 1A2 inhibitor) inhibits metabolism of

Answer 32

caffeine

Question 33

Elimination | 1st order elimination

Answer 33

!st order elimination-- Rate of elimination proportionate to concentration of drug in body. Plasma concentration of a drug decreases exponentially over time ---1/2 life

Question 34

Elimination 1st order | Half Life Elimination

Answer 34

Half life is constant no matter how much of a drug is given Concentration decreases 50% EVERY HALF LIFE Steady state is reached after 4-5 half lives

Question 35

Elimination Zero order elimination | less frequent

Answer 35

Rate of elimination is constant regardless of concentration. Occurs when drugs saturate elimination processes. Drug concentration decreases in linear fashion over time. ( ETOH + elimination 15mg /hr)

Question 36

Interactions/reactions GI absorption interactions

Answer 36

``` drug A inhibits absorption of Drug B Drugs A and B bind in GI tract Alteration of GI motility Alteration of pH Alteration of intestinal flora ```

Question 37

Interactions/reactions | Protein binding

Answer 37

Coumadin and highly protein binding drugs

Question 38

Drug reactions

Answer 38

Type I-non allergy | Type II--Hypersensitivity i and II reactions HIT

Question 39

Pregnancy and drug classification

Answer 39

Category A--Ok-no fetal risk Category B--Ok-no fetal risk Category C--Clinical Judgement -potential benefit> than potential risk to fetus Category D Category X--Do NOT GIVE