Lecture 1

Question 1

What is pharmacokinetics?

Answer 1

The study of the concentration of the drug in the blood plasma during the processes of absorption, distribution, metabolism, and elimination. What body does to drug.

Question 2

What is pharmacodynamics?

Answer 2

The study of the mechanisms by which drugs produce their intended therapeutic effects. What drug does to body.

Question 3

What is pharmacotoxicology?

Answer 3

The study of the physiological mechanism by which drugs produce adverse side effects.

Question 4

Trade Name

Answer 4

Patented, expires after 17 years.

OTC drugs can be different formulations / different drugs

Question 5

Generic Name

Answer 5

Common name, noncommercial

Question 6

Chemical Equivalence

Answer 6

Two drugs contain the same amount of an identical chemical compound

Question 7

Bioavailability

Answer 7

Absorption rate and extent

Question 8

Can 2 drugs be chemically equivalent with different bioavailability?

Answer 8

Yes. They can dissolve at different rates so are absorbed differently, causing changes in time of onset and intensity.

Question 9

Why enteric coated drugs and the problem with them.

Answer 9

They are designed to dissolve in intestines b/c:
1. protect drug from stomach acid or pepsin.
2. protect stomach lining from drug (gastric discomfort).
Problem is gastric emptying is variable minutes to 12 hours, so alters time of onset. Might NOT dissolve at all

Question 10

Aspects of good clinical trial

Answer 10

1. Controls
2. Random Assignment
3. Blinding

Question 11

Stages of Drug Development

Answer 11

Stage 1: Preclinical testing on animals

Stage 2. Clinical testing on humans.

Question 12

Preclinical Trials

Answer 12

On animals;
Evaluated for:
1. Toxicity
2. Pharmacokinetic properties
3. Potentially useful biological effects.
1-5 years
Then apply for Investigational New Drug status

Question 13

Clinical Trials

Answer 13

2-10 years
4 Phases
1-3 are before market
4th phase after marketing

Question 14

Phase I Clinical Trials

Answer 14

Conducted on healthy volunteers.
3 Goals:
1. Evaluate drug metabolism
2. Pharmacokinetics
3. Biological Effects

Question 15

Phase 2&3 Clinical Trials

Answer 15

Conducted on patients.
Given to 500-5000 patients for 3-6 months
Evaluated for:
1. Therapeutic Effects
2. Dosage range
3. Safety
4. Effectiveness
Then apply for New Drug Application (NDA)

Question 16

Phase 4 Clinical Trials

Answer 16

Post marketing surveillance

Observe in general population

Question 17

Limitations of Clinical Trials

Answer 17

1. Poor information on women and children

2. Failure to detect adverse effects (50%)

Question 18

IM & Sq

Answer 18

Only barrier is capillary wall. Lipid soluble can diffuse across and pass through fenestrations. Polar ions only pass through fenestrations.
Adv: suitable for poorly soluble drugs and depot preparations
Disadv: Pain, inconvenience, injury, variable rate of absorption r/t blood flow and water solubility of drug

Question 19

Oral

Answer 19

2 Barriers:
1. epithelial lining of GI tract: P-glycoprotein can pump drugs out of cells back into lumen of GI
2. Capillary walls
Variable absorption pattern

Question 20

Variability of Absorption in oral route

Answer 20

1. Solubility and stability of drug
2. Gastric and intestinal pH and related enzymatic breakdown.
3. Gastric Emptying time
4. Food in gut
5. Coadministration of other drugs
6. Special coatings
7. Circulation through hepatic portal system

Question 21

First Pass Effect

Answer 21

GI–> Hepatic portal vein–> Liver–>inferior VC to systemic circulation OR enterohepatic recirculation–>bile duct–>duodenum–>hepatic portal vein…

Question 22

What is the difference between a drug and a poison?

Answer 22

Dose

Question 23

Half life

Answer 23

Time it takes for the concentration of a drug to decrease by half.

Question 24

Area under the curve (AUC)

Answer 24

Total amount of drug from the time it enters the blood until it disappears.

Question 25

Bioavailability

Answer 25

The percent of total drug dosage that enters blood stream.

Question 26

Bioavailability formula

Answer 26

AUC (mg)/dosage (mg) x100

Question 27

In general, how dooes route of administration influence bioavailability?

Answer 27

Parenteral has the highest, with IV = 100%

Question 28

Bioequivalence

Answer 28

Manufacturing guidelines that require 2 preparations of the same drug (trade vs Generic) to have smae AUC and same Cmax, increasing the likelihood they will have the same biological effects

Question 29

Variables influencing Absorption:

Answer 29

1. Rate of dissolution
2. surface area
3. blood flow
4. lipid solubility
5. GI function/contents
6. pH partitioning

Question 30

Influences on BBB

Answer 30

Infants, elderly, inflammation, infection.